In the sixth season-opener, the good reverend's (Eric Camden) stress level rises when he learns that Matt has lost his job at the hospital and is relying on his friends to find him new work. Meanwhile, Simon is adding to Eric's tensions by pressuring him to let him get his learner's permit. At the same time, Lucy breaks off her engagement to Jeremy and just cries in her room and refuses to discuss what happened in New York between her and Jeremy. Even lodger Robbie, still longing for Mary, is moping around the house when she returns to New York to be with Wilson. Lastly, Annie's behavior has Eric wondering what's going on with her, while she is overcome by hormonal changes and suspects she's pregnant--- but later finds out it's menopause.
Simon decides to stand up for bullied student, Mick at school, only to have the boy tell him that he is going to shoot his tormentors. Meanwhile, Robbie decides to give Ruthie a playful new nickname ("Snooky"), but at the same time Ruthie comes up with a less-pleasant one for Lucy ("Lady Liberty") after breaking off her engagement to Jeremy in New York. Also, Eric gets a visit from an old female friend, Merle, with some family issues of her own. Lastly, Mary gets serious with pursuing the career as a firefighter, but things don't turn out the way she had planned.
Simon considers dating a 16-year-old pregnant girl named Sally who he meets on the bus. Although, there is more to Sally's past than what she is letting on. Meanwhile, Annie decides to accept Robbie's offer in renting the room over the Camden's garage that both Lucy and Matt were hoping to get. Also, a carpenter pretends to fake an injury while working on the Camden's garage and tries to sue them. Lastly, Mary gets more serious with being a firefighter, mother and wife to Wilson and Billy.
Eric tries to arrange a romantic evening with Annie, but Annie keeps turning down every attempt he throws at her. At the same time, Annie takes Eric by surprise with the news that she would like to quit college and to start teaching to help get her out of her depression. Meanwhile, Simon is at risk of being fired from his new job at the pizza parlor by his excessive tardiness and discovering that waiting tables takes more people skills than he's equipped to handle. Also, Robbie sets Lucy on a date with one of his friends while Matt is concerned about a woman who keeps showing up at the clinic a lot. Lastly, Mary performs terribly in fire fighting training distracted by her consuming relationship with Wilson.
As Annie begins teaching, she inadvertently gives a student some bad advice. At the same time, Eric and Annie painfully discover how much their constant arguing is affecting the family. Meanwhile, Lucy and Robbie finally face up to their feelings after she intentionally sabotages one of his dates out of jealousy. Also, Cheryl goes to Eric for some guidance in her relationship with Matt, but she misinterprets the reverend's input in the matter. Also, Simon is attracted to a girl who is dating one of his friends. Lastly, Mary is left to mull over Wilson's marriage proposal and it's even more confusing when she has a romantic encounter with a fellow firefighter trainee who shows an interest in her.
Lucy and Robbie argue over who should tell Mary about their emerging relationship. Meanwhile, Matt worries that a young woman in his study group might be a victim of physical abuse at the hands of her belligerent boyfriend. Elsewhere, Eric's sister Julie shows up at the Camden house with her toddler Erica and annoys Annie as she tries to prepare a lesson for her class. Lastly, Simon meets up with an old girlfriend, Sasha and they both try to catch up on their personal lives.
Mary's sudden arrival has everyone in the family wondering what happened between her and Wilson. Are they married? Did they break up? Only Mary knows and she's not telling---at least not yet. Her presence delights Annie, who goes out of her way to make her daughter comfortable, even offering her the coveted garage apartment. But not everyone is happy to see her. Ruthie feels that Mary owes everyone an apology for the actions that led to her initial ouster from the Camden home.
Matt, Lucy, Simon and Ruthie are banished to the garage apartment after protesting to Annie's decision to give the place to Mary, but then the roommates begin voting each member vies for sole ownership, just like the TV show "Survivor". Meanwhile, Eric and Annie are not seeing eye-to-eye on Mary's situation as she is now returning home and is wondering on what's next in her life. Elsewhere, Robbie is nervous about meeting his new girlfriend's parents--- especially her father when he must show that he is serious about his relationship with his girlfriend Joy.
Mary and Lucy seek their parents for expertise in matchmaking and ask their parents to find new boyfriends (and potential husbands) for the both of them. Robbie argues with Joy about spending so much time together when she insists on seeing him right away. Meanwhile, Simon and Matt are looking for girls the old-fashioned way- using the twins as adorable bait to attract women, but doesn't go as quite planned. Lastly, Robbie unknowingly becomes the key to finding Joy's missing younger brother, Joseph when he finds a stray dog in the street that belonged to him.
Annie's father, Charles shows up at the Camden household for a weekend visit as Ginger supposedly needs to get away for a bit. But Eric forgot to tell his wife about it and nearly everyone in the Camden household is too busy to spend time with the elderly man. Meanwhile, Grandpa Charles takes Simon to get his learner's permit for driving and they end up being the center of a televised police-pursuit. Lastly, Eric lies to Annie about his plans for the day, which include a trip to Glenoak Hospital.
Annie quits her job at the private school without discussing it with Eric first, and he feels completely left out. Also, Mary tries to call Wilson and learns from his landlord that he has moved out of his apartment. Meanwhile, Simon uses Robbie's car to practice driving and he accidentally gets him in trouble when Simon smashes into Matt's car. Robbie's brother, Ronald, stops by at the Camden home for a visit. Mary also gets an unexpected visitor--Ben, the fireman she kissed, who drops by unannounced for dinner. Lastly, Ruthie's old nemesis teacher Ms. Riddle returns when she starts working at Ruthie's school.
After various personal items disappear from the house, the family finds Ruthie in the garage apartment entertaining a friend with the pilfered items. The would-be bandit explains that she is hiding her pal from a pair of older boys, who have been harassing the girl because of her Muslim background. Touched by her plight, Mary and Lucy try to get their neighbors to sign a petition in support of the girl's family. Matt and Simon, however, decide on a less civic solution and go hunting for the perpetrators.
Simon persuades his parents to let him go to a party after they meet his friend; a senior who promises to look out after him-- but not everything goes so smoothly-- especially when he comes back home completely drunk, which puts his siblings in a terrible position on what do. Meanwhile, Matt gets mail from two medical schools that he applied to, but he's hesitant to open the letters, and the letters eventually end up with Ruthie. Lastly, Mary and Lucy take the same classes at an area college and Mary goes with Lucy and her friends to a bar.
St. Valentine's Day delivers a few surprises for the Camden family as a grounded Simon is asked out by a senior, Maria. Annie's attempt to surprise Eric with romantic Valentine's plans backfires and results in a big fight. Meanwhile, a nosy Mary discovers Robbie's plans with Joy. Lucy runs into her ex-fiance Jeremy outside one of her classrooms and finds out that he is going to the pool hall and meeting a "friend" for Valentine's, which is to Lucy's surprise. Mary also meets up with Wilson who also has a new girlfriend, her old friend, Corey Conway. Also, Matt seeks his fathers help with his love life and wants to get serious with a girl, which leads him to seek out old girlfriends as to why they're no longer together. Lastly, Ruthie is hesitant to go to a party because her friend tricked her into asking out a boy she's already going out with.
Determined to settle down before heading off to medical school, Matt goes in search of a woman to marry. Matt talks with a doctor he works with about wanting to get a life-long mate. Sarah Glass, a co-worker who catches Matt's eye after the future doctor decides to start looking for a bride. Her parents, Rabbi Glass and Rosina Glass and family are Jewish and very concerned for the two. Ruthie tries to set her brother straight by telling him not to do "anything stupid." Eventually concern grows to fear for both families as both Matt ad Sarah do not come home after their second date together in less than 24 hours.
Matt stays out all night with Sarah and they secretly elope, but when facing their parents they're only able to summon the courage to say that they're engaged. A worried Annie tries to calm Eric down, who is convinced that Matt did something foolish. Meanwhile, Lucy and Mary search for Ruthie because they suspect that she knows what really happened during Matt's night out. Ruthie and Matt agree to keep the marriage a secret until a Jewish wedding in a few months.
Annie frantically cooks Jewish dishes as the Camdens prepare to head out to a Shabbat dinner at the Glasses. Simon asks' Matt and Sarah if he can bring his friend Morris to the dinner. Matt agrees to allow Morris to come to the dinner as he is half Jewish. Although, that does not go as he planned as he is not very knowledgeable about his faith. Lucy and Mary play sick to try to skip the outing so they can stay home with Robbie. While home, Mary flirts with Robbie. Lastly, Eric and Annie are unable to handle everything when they are shocked to find out during dinner that Matt is considering to convert to Judaism.
Matt and Sarah argue over their wedding plans and their agreement to forego buying an engagement ring and seek Eric for advice, who isn't happy with Matt for getting engaged in the first place. Through the advice of Eric, Matt buys Sarah a fake engagement ring. Mary and Lucy fly to Buffalo for a weekend, or at least that's what Lucy thinks as Mary makes plans of her own. While there, Lucy meets a police officer named Kevin who confiscated her bag, and he invites Lucy and Mary to double-date with him and his brother, but with a big surprise in store for Mary.
A startled Eric catches Mary and Lucy in the kitchen with two guys in the middle of the night. The guys, Kevin and Ben, end up spending the night in the living room with Mary and Lucy. Patty-Mary, Ben and Kevin's sister calls the house to inform Ben and Kevin that their mom is going out with a neighbor. Eric suspects that Ruthie knows a secret about Matt and Sarah and thinks they are married already. Also, the twins switch out of their cribs into beds. Meanwhile, an older couple seeks guidance from Rev. Camden when they can't seem to let go of their 44-year-old son, Jeromiah who has runaway from home.
In this very special episode, prior to the death of Sgt. Morgan, Ruthie corresponds with the soldier by e-mail for a school project and she shares the letter with her family. Also, "The Colonel" drops by to tell Ruthie about Sgt. Morgan's death. Ruthie and Eric hold a memorial service in honor of Sgt. Morgan with actual Marine Corps. and family members of Morgan in attendance. In honor of the late Sgt. Morgan's service and commitment to his country, Eric asks everyone to advocate good deeds and go out into the commuity, as the family does. Also, Ruthie makes a video where she is singing Tom Petty's "I Won't Back Down" and is sending it to the Marine Corps. in memory of Morgan.
Matt and Eric meet with Rabbi Glass to discuss wedding plans, and Eric learns that he is playing a small roll than he had originally planned. Matt and Sarah are prepared to have their wedding, but Rabbi Glass and Eric can't seem to agree on their children marrying out of faith and Matt converting to Judaism, and call the wedding off. Annie prepared for much less visitors to attend the rehearsal dinner and gets very flustered over the fact she does not have kosher food, and that she doesn't have enough food in the first place. Julie and Hank call to tell Annie that Julie is going into labor. Ginger and Charles are prepared to fly to Glen Oak, but Charles gets lost at the airport. Simon is convinced that Matt will ask him to be his best man, and gets angered when he asks Robbie. Meanwhile, Ruthie tells Robbie that she wants his room for herself after Matt moves out. Ben proposes to Mary, but he gets an unexpected answer. While at the airport waiting for her grandparents, Lucy finds a guy and later invites him on a date to the wedding, as she is fighting with Kevin over moving arrangements.
In the sixth season finale, Matt and Sarah grieve over Eric's decision not to attend the nuptials following his argument with Rabbi Glass over Matt's conversion to Judaism. Hoping to patch things up between their fathers, Matt and Sarah seek their mothers' help in persuading the holy men to put aside their differences before it's too late. Annie and Rosina cunningly convince their husbands to co-officiate the wedding incorporating both the Jewish and the Christian vows into the service. Ben and Kevin come to Glen Oak to meet up with Mary and Lucy so that they can resolve their problems. Meanwhile, Robbie tries to figure out why Ruthie wants him to move out of the Camden household.