Lexi is a typical alpha female; a mean girl. She often puts people down and tries to mess with them, especially the ANTs. She's always been naturally beautiful and has won many beauty pageants in her childhood, thus making her popular. Previous plays she starred in were Grease, Annie, and Fiddler on The Roof. She is very protective of her popular status, and doesn't like it when other talented people are around her. She tries to sabotage people for the sake of her popularity, such as Chyna and Abigail, but it usually backfires. She also considers socializing with certain people bad for her popularity.
In TransplANTed, she greets Chyna by knocking her out of her chair. Later, she hosts a party at her house to which Chyna, Fletcher and Olive show up at, much to her displeasure. When Chyna sings at the party, she is impressed yet jealous with her talent. At the end of the party Olive gets blueberry yogurt on her outfit and she shrieks that her mom would kill her.
In ParticipANTs, it is revealed she is captain of the cheerleading squad. Chyna and Olive both try out for the squad, but only Chyna makes it, which is secretly part of her plan. Chyna becomes "friends" with Lexi, Paisley, and the other cheerleaders, while Olive feels abandoned by Chyna. Lexi overworks Chyna at practice, so Chyna gets injured and loses her voice due to too much cheering. At the school musical audition, Lexi does a music number about candy and Chyna does a method acting thing about not being a freak. Chyna gets the part to Lexi's dismay.
In The PhANTom Locker, she appears twice briefly and tricks Cameron by telling him a lie of how to get rid of a person. She then appears when he realizes what she said wasn't true.
In SciANTs Fair, she makes Cameron go into the trash to look for her sunglasses, and they end of being in her backpack. Then, they find Principal Skidmore's cell phone and keep it for their andvantage. She gives all of the foriegn language teachers the week off. Then, she and Cameron find out that Skidmore made a reward for whoever finds the phone. At first, she wants to give it back for $50, saying she ould buy 2 bottles of end of summer bronzer. But, Cameron convinces her to keep it longer so that they could get $100 and four bottles of end of summer bronzer. Then, she sees Skidmore talking to Cameron's dad and gets worried, making Cameron give the phone back, although they get caught and she tries to blame Cameron. However, Skidmore doesn't believe her and she gets into trouble in the end.
In StudANT Council, she denied Chyna's entrance to the school dance, forcing Chyna to run for Student Council.
In The ReplacemANT, after Olive becomes the new history teacher, she and Chyna get detention from "Ms. Doyle." Later, she pulls a prank in the history room.
In CANTonese Style Cuisine, she and Paisley try to figure out why she hasn't been invited to a fellow cheerleader's birthday party.
In IgnorANTs Is Bliss, she enters Gibson's dog show.
In America Needs TalANT, she auditions for America Needs Talent, and she and Chyna are the only ones who get to go to Hollywood. Later, she tries to steal Chyna's song in which she fails to do so and ends up publicly humiliating herself on television instead. In the end, she and Chyna make up.