Divorced working mother Christine Campbell owns a women's 30-minute workout gym, successfully juggling the daily stresses of motherhood and her business.
Upon learning that Richard and "new" Christine are enjoying an intimate relationship, Christine becomes determined to make her own romantic conquests.
Upon learning that her close friend Barb is responsible for matching up "new" Christine and Richard, Christine allows Barb to set her up on a blind date of her own.
Upon learning from the gloating Matthew that Christine is out enjoying her fifth date with an attorney, Burton, Richard does what any self-respecting ex-husband would do.
Christine gets nervous when Burton tries to take their relationship to the next level.
Concerned about the uniformity of Ritchie's schoolmates, Christine takes it upon herself to help diversify the student body at his exclusive private school.
Everyone expects Christine to fall apart emotionally after her breakup, but she insists she is fine and looking forward to spending some time on her own.
Christine feels pressured to throw an extravagant party for Ritchie's ninth birthday, his first involving children from his new private school.
Christine tries to behave maturely when Richard brings "new" Christine to breakfast with Ritchie so they can get to know each other.
Christine's former marriage counselor comes into the gym, leading to some awkward moments between the two women.
Christine objects when Richard and "new" Christine want to take Ritchie to a Rolling Stones concert.
Shut out once again by the judgmental moms at Ritchie's school, Christine is overjoyed to finally make friends with another down-to-earth working woman, Belinda.
While volunteering at the spring carnival at Ritchie's school, Christine is surprised to learn that there's a hot new dad at the school--and excited that it's her ex-boyfriend, Burton.
Christine and Mr. Harris are ready to consummate their relationship -- until Barb says something that gives Christine reason to worry.
After a pretty young waitress flirts with Mr. Harris, Christine worries he will leave her for someone younger and visits a plastic surgeon.
Christine is shocked when a new dad at Ritchie's school calls her a "meanie mom" for being judgmental and standoffish, and dumps her for Marly and Lindsay.
Christine promises to accompany Mr. Harris to an important event, but leaves him hanging when Ritchie's soccer game runs long.
Christine attempts to stop sulking and get over her breakup with Mr. Harris.
Christine reluctantly lets New Christine set her up on a blind date, but the date goes from bad to worse as Christine discovers he is not who he made himself out to be.
When Christine learns that Richard and New Christine bought the house she had always dreamed of, she tries to contain her jealousy and attempts to feel genuinely happy for them.
Christine considers taking a walk on the wild side in order to make Barb think she's not a square.
Matthew and Barb pretend to be inseparable after Christine learns they spent the night together and forbids them to see one another.
When Christine's gynecologist suggests that she may be experiencing perimenopause, Christine tries to take charge of her hormones.
It's the first day of fourth grade for Ritchie. When Christine and the other moms meet the class' disarmingly handsome new teacher, Daniel Harris, they decide to schedule a few parent-teacher conferences immediately.
Worried about Richard's indiscriminate dating habits and reluctantly realizing that she misses New Christine as well, Christine vows to bring the couple back together.
When Christine learns that Jeff, the new man in her life, is a grandfather, she is forced to rethink the relationship.
Christine is surprised when Ritchie expresses a newfound interest in religion after returning from a church festival with Richard and New Christine.
After announcing that she and her husband are getting a divorce, Barb moves in with Christine.
When manipulative moms Marly and Lindsay convince Christine to serve hot lunch at Ritchie's school, Christine finds herself serving with Stan.
Christine's attraction to Ritchie's teacher, Mr. Harris, causes a scene at a school fundraiser---especially after Ritchie wins a playdate with him.
When Christine realizes she can't afford the newly raised tuition at Ritchie's school, she tries to get help from everyone except the person who is offering it freely: Barb.
Annoyed that Ritchie finds his weekends with his dad more fun than his weekdays with her, Christine decides to make Richard responsible for helping Ritchie complete a big homework assignment.
Now that Barb is a co-owner of Christine's women's gym, the two women don't always agree on how to run it.
When Christine's modest hybrid car crashes into Marly's gigantic sports utility vehicle in the school parking lot, the women agree to take care of their own damage.
Christine reluctantly signs Ritchie up for soccer after Mr. Harris, informs her and Richard that Ritchie is having trouble making friends.
After Christine convinces Matthew to let her come with him to his friend's party, she learns about her brother's world outside of their home.
Christine resents that New Christine is reaping the benefits of all the time Christine spent trying to perfect Richard while they were married.
Sleep-deprived Christine's mood swings cause tension with everyone around her until she tries some potent new sleeping pills.
Christine worries that she has lost her ability to attract men.
Eager to make a difference in the world, Christine volunteers to collect signatures supporting an issue she doesn't quite understand--as she finds out from a competitive signature-seeker, Audrey .
Intending to send an e-mail about her relationship with Mr. Harris only to Barb, Christine accidentally sends the scandalous message to all of the parents at Ritchie's school, almost getting Mr. Harris fired.
Christine's controlling nature causes her to go too far and jeopardize one of Richard's construction jobs.
At the wedding of her ex-boyfriend, Christine agrees to be the designated driver for Richard, New Christine and Barb.
Ritchie is excited to go on his first overnight camping trip with his class, but Christine worries about him making it through the night without her.
Christine is stunned to discover that a night of fun may have resulted in an unforeseen consequence.
Christine proposes to Barb to save her from being deported.
Richard asks Christine to return her wedding ring -- previously his mother's -- so he can use it to propose to New Christine.
After Barb is profiled in a business journal, new clientele hits the gym and business really picks up.
Christine agrees to go out with a children's entertainer specializing in reptile parties in order to get Ritchie into the Reptile Club.
When Ritchie stops telling Christine he loves her, she is devastated and asks Richard to have a baby with her so she can have a new child to love her the way Ritchie used to.
Christine and Barb go on a double date, but only one gets asked out a second time.
Richard joins Christine and her new boyfriend, Patrick, on a dinner date.
Christine and Richard argue over whether to allow Ritchie to audition for a television commercial after his surprisingly wonderful performance in a school play.
Christine thinks she has the perfect boyfriend, until he shows a shockingly bizarre side of himself.
Christine dreads going home to see her mother at Thanksgiving, but she discovers a secret they have in common.
Christine and Barb may lose their gym franchise when a representative from their parent company informs them that a contractual clause has been broken.
When Christine and Barb can't get a loan to keep their gym franchise, they decide to transform their building into a day spa.
Christine realizes that one of the fathers at Ritchie's Parents Orientation was the seventh grade classmate who ruined her reputation, and she decides to take revenge.
New Christine loses all her inhibitions at a spontaneous bachelorette party Christine and Barb throw for her in Las Vegas.
Christine searches for the independent woman inside herself after Barb and Matthew move out.
Christine accuses Richard of bad parenting when Ritchie gets hurt at a skateboarding party, but soon surpasses him as the worse parent when her over-protectiveness backfires.
Christine finds herself the solid, dependable one in a new friendship with a fellow mom, Francie, at Ritchie's school.
Christine and Richard help Marly and Lindsay through labor, evoking memories of Ritchie's birth -- and possibly rekindling romantic feelings.
Fed up with the mean moms at Ritchie's snotty private school, Christine decides to enroll him in public school.
Christine uses her expertise as a gym owner to help Matthew lose weight.
To convince everyone she's fine with Richard's remarriage, Christine pretends she and her date, Todd are in love.
Feelings are reawakened between Christine and Papa Jeff at Richard and New Christine's wedding, until Christine receives some shocking news.
Christine and Matthew fly to the Bahamas to help get Barb an illegal visa after she is thrown in jail by immigration.
Christine and Richard meet up with some old college buddies and are shocked to see how much their friends have aged.
Christine thinks she is dying after Richard awkwardly spots an irregular mole on her chest, and panics when she can not get in to see a doctor fast enough.
After Barb has her lawyer send over divorce papers, Christine hires an aggressive divorce attorney, who convinces her that Barb owes her alimony.
Christine begins seeing a therapist, although it's unclear whether Christine is interested in pursuing therapy or romance.
Christine surpasses the Meanie Moms in popularity when Ritchie is asked to a dance by the most popular girl in school.
Max points out to Christine her tendency to flake when things get tough, and tries to teach her how to follow through.
Richard asks Christine to set him up on a date to help him get over New Christine.
Barb insists that Christine join her on a date with Dave, the immigration officer she has been seeing.
When Christine finds out Ritchie is the school bully, she decides to set a good example by making amends with the woman she bullied as a kid.
Christine attends her neighborhood Christmas party where she learns a juicy secret about her neighbor.
Christine tells her therapist she's in love with him, but his response is not what she expected.
Christine finds herself falling in love with Max until her ex-boyfriend, Mr. Harris, comes back into her life.
Christine feels left out as Richard and New Christine plan for their baby and decides she wants one too.
Christine comes into some money and must decide whether to splurge on a designer dress or help starving children.
Christine urges Ritchie's school principal to let the class take the subway on a field trip in order to learn real-world skills.
Christine decides Ritchie deserves to go on a family vacation like his friends, but her plans to take him to Florida don't turn out quite as she had intended.
Old Christine takes New Christine out for some pampering while Richard prepares a surprise wedding.
Max offers to help Christine make a major life change after she realizes that her five-year car lease is up and her life hasn't evolved in all that time.
Christine mistakes a hot cop for a stripper and New Christine goes into labor.
Christine feels intellectually inferior after meeting Max's friends at their "surprise" engagement party, driving her to make a decision.