- „Just call me karma, babe. And karma is a bitch”
- —Jen Clark[src]
Jen is the daughter of Charles and Tracy Clark, and is Naomi's older sister. She returned to Beverly Hills following a departure to attend Yale University and travel Europe, reuniting with her father, her sister and a number of other people. She used to be Kelly Taylor and Valerie Malone when she was in high school. She dropped out of Yale and married a wealthy French man Olivier Le Sage, when he cheated on her. She left for Paris and come to Beverly Hills to visit Naomi.
Following her return, Jen has a brief encounter with Ethan Ward, Naomi's ex-boyfriend, in which she claims to have secretly been his "first". Soon afterward, she and her sister meet with their father, who Naomi has been separated from following his split with Tracy. Jen pressures Charles to give Naomi access to her trust fund, and Charles is ultimately forced to agree. Jen then begins a relationship with Ryan Matthews, a young teacher at her old school, West Beverly High.
She and Naomi also plan to buy a home together, intending to share the cost. However, when Jen claims to be having financial difficulties, Naomi takes care of the cost herself, with Jen stating that she would pay her back later. After the two have moved in, Naomi confronts Jen as additional expenses mount. Jen reveals that she is having greater financial misfortunes than she's let on, and Naomi becomes sympathetic.
Jen joins Naomi at the prom as she accompanies Ryan while he is on duty. At the event, she is reunited with her old guidance counselor, Kelly Taylor, who recently dated Ryan as well. Tension abounds between the women, due largely to Kelly holding a low opinion of Jen's personal character. After the prom, Jen receives a phone call which leaves her frustrated, prompting her to state that she is actively pursuing a divorce. Later, Jen becomes resentful when Naomi claims control of the house and throws an after-prom party. Earlier in the evening, Naomi had attended the prom with Liam Court, who'd asked her to keep their personal discussions private.
However, he is unaware that Naomi had already revealed things about him to Jen. Upon discovering this later, Liam was left to believe that he'd been betrayed. He then followed Jen to bed, where the two acted on their mutual spite for Naomi. Upon finding Liam half-naked, Naomi left the room after declaring their relationship over. Liam then became remorseful when Jen identified herself as Naomi's sister. Believing Annie Wilson to be the other girl, Naomi chastised her out in the open. This prompted Annie to leave the party while reporting the underage drinking to the police. Later, Naomi was "comforted" by Jen. The party came to an end, however, when police officers arrived on the scene.
Jen continued to manipulate and sponge off her sister Naomi for several months. She kept Liam from telling Naomi the truth about Prom Night by approaching his mother. Unbeknownst to Jen, Liam recorded one of her confession/threats on his cellphone as proof, but later erased it. Jen and Ryan continued to date in an open relationship which allowed her to date richer boyfriends for perks, but she got jealous when Ryan started dating a bartender. Jen and Ryan decided to be exclusive and bonded over a failed camping trip.
Under the guise of divorcing her husband, Jen took a large sum of money from Naomi to buy a racing horse of all things. At some race the horse took first place and won the grand prize. At the same race several of the high school students set up an elaborate Oceans 11-type stunt to ruin Jen. Naomi overheard Jen reveal everything to Liam and told Jen to get lost. Ryan also caught Jen in a lie about receiving the horse as a gift, and also learned she'd slept with Liam, which led to him breaking up with her. Jen returned to Los Angeles with her husband Olivier Le Sage, who bought Naomi's house and the beach club for Jen. Jen also managed to convince her father to let her control Naomi's finances until Naomi is an adult. Naomi told Olivier about Jen's affair with Liam. After cheating on Jen, Olivier paid her $16 million dollars as part of their reconciliation cause. Naomi chased Jen straight into the OB/GYN where she finally found out Jen was with child, spotting a previously unseen baby bump.
In the fifth episode of Season 3, Jen gave birth to Ryan's child. She and Ryan shared a brief kiss after the birth of their son. Jen hired Debbie as her personal assistant. After Jen finds out what Mr. Cannon did to Naomi she is furious. She, and Ryan, decide to help Naomi. Naomi and Jen start being friendly after Naomi sees how much she cares about her. Jen soon left town leaving her son Jack to live with his father Ryan after realizing she was a bad mother. Jen comes back in the episode Women on the Verge. She is warmly greeted by Naomi. And coldly greeted by Ryan. She tells Ryan that she wants to stay in Jack's life. After talking with Debbie, Ryan allows it.
Jen appears with her son in Naomi's house at the end of sixteenth episode.Naomi mentions to Jen that she started her own business, Naomi Clark Events, and Jen continues to act like she could care less. William Paddington, Naomi´s client shows up with Jen. Jen flirts with William while Naomi does her presentation. William stops Naomi mid-presentation to tell her he’s hiring her and to set up a date with Jen. After Jen confides in Naomi about her fear that she’ll end up alone in life, Jen leaves to go out with William and asks Naomi to babysit Jacques while also planning her event. After Jen and Williams bail Naomi out, Naomi gives William his wedding ring. Jen tells him he’ll let Naomi plan the party or she’ll call his wife. Later, Naomi tells Jen she wanted to impress her and Jen tells Naomi her whole life is impressive.
Jen is with the girls at Naomi’s for a tarot card reading. Jen tells everyone she met a man while playing tennis and Naomi tells everyone she thinks PJ may be “the one”. Naomi tries to impress PJ, Jen comes out and we find out the guy she had a connection with at the club was PJ. The girls argue over who has dibs, and then Jen says whoever PJ asks out will get him. The truce ends when Naomi spills tea on Jen’s dress, w Later, Jen gives Naomi some moisturizer from France as a peace offering. Naomi thinks the moisturizer is tainted, so she goes to get another in her bathroom and Jen locks her in there.
Jen overhears the conversation between Naomi and Annie. Naomi goes to the music festival and finds out Jen switched “the dress” with a clown outfit. Jen shows up in “the dress” just in time for PJ to show up. PJ soon excuses himself, as he has a emergency call about his vineyard. Jen and Naomi later argue, again, and accidentally fall into a mud pit, which they then wrestle in. Someone random knocks Annie in too, so she yells that PJ left for Napa an hour ago to Naomi and Jen. Naomi and Jen then apologize to each other and say they’re jealous of each other. Jen then tells Naomi that she’s leaving for LA with Jacques. Annie later hands Naomi a letter that Jen left. The letter says that she’s going to Napa.
Jen returns from Napa to a furious Naomi. Jen says she had a horrible flight back and Naomi doesn't believe her until Jen throws up. Naomi thinks Jen is making this all up so she can just lounge around at Naomi's. Naomi shows Jen a box of some old things, including a picture of them when they were little at Naomi's birthday party and Jen is wearing Naomi's birthday dress. Naomi also shows her a letter Jen wrote to her with the floor plan of their new house and showing that her bedroom is the one with the smallest closet. Jen later tells Naomi that she did these things because she cared for her; that the dress would really look awful on Naomi and the bedroom was the only one where you couldn't hear their parents shouting. Jen leaves the next day, making Naomi think she has lost her. Later, Jen calls Naomi while Naomi is in bed with PJ and they reconcile, but Jen tells Naomi that PJ has a 'scandalous secret' and that it was good that neither of them got with him leaving Naomi feeling uncomfortable.
- Jen had her eye on three of Naomi's ex-boyfriends: