Bring It On: All or Nothing

Britney Allen's living a 'dream life' as the cheerleading captain and girlfriend of the star quarterback of Pacific Vista High School. Her nemesis is the highly ambitious Winnie Harper. Her life changes dramatically when her father loses his job, and the family must relocate to the disadvantaged city, Crenshaw Heights, which Britney, being the "White Girl", takes quite a while to adjust to.
She meets Camille, cheerleading captain of the Crenshaw Heights 'Warriors' and her friends and fellow cheerleaders, Kirresha and Leti. She also meets Jesse, a male cheerleader and the only person who is nice to her on her first day. Britney, at the urging of Winnie, has already vowed to never cheer for another team (as this would make her a 'cheer whore'), but after being dared by Camille and Jesse to show up at the cheerleading tryouts, Britney impresses everyone with her cheerleading skills and experience. Camille, after being persuaded by her friends to "do it for the squad," reluctantly invites her onto the squad. Britney and Jesse become close and eventually kiss.
Around this time, singer Rihanna announces a television special where all high school cheerleading squads can compete, with the winners appearing in a music video with her and winning new computers for their school. Winnie finds out that Britney's cheering with the Warriors and reveals this to her friends. A week later, Britney lies to Camille, telling her that she can't cheer at the next game as she's holding a memorial service for her dead dog; when she's actually going to Pacific Vista's Homecoming dance. Camille and Jesse arrive at Britney's to offer their condolences, and when they see Britney and Brad dressed up for the dance, Camille kicks her off the squad.
At the dance, Winnie reveals to everyone that she has been sleeping with Brad behind Britney's back causing Britney to dump him and end her friendship with Winnie, telling her that she's "too much of a backstabber to have any real friends". On the day of the auditions, Britney arrives at the Warriors' bus and comes to wish them good luck. When Winnie, with the rest of her team, makes fun of the Warriors, Britney stands up to Winnie and defends them. Camille, impressed by this, lets Britney cheer with them again. Jesse, however, is still mad at her for not telling him that she had a boyfriend before they had kissed. Both of the rivaling teams show their performances. At the auditions, the two finalists are Pacific Vista and Crenshaw Heights. PV wows the audience with their routine and Camille starts getting worried. Then Britney points out that all their steps are repetitive and that they have their secret weapon: Krumping. Now dressed in streetwear instead of their regular uniforms, steps on stage during PV's performance and begins mirroring their steps. Finally, they begin krumping, wiping PV off the stage and impressing Rihanna with their routine. After the Warrior's performance ends, Winnie approaches Rihanna and insists that Crenshaw Heights should be disqualified ("or arrested") for interrupting PV's routine. This leads to an argument between Winnie and the rest of the Pacific Vista squad, during which Britney notes, "Spirit Law states that if there's a cheer mutiny, a squad can vote to replace their captain."
Everyone present, even Rihanna and the other performing squads, vote to replace Winnie as the Pacific Vista High cheerleading captain. Winnie protests, dismissing CH's style as "ghetto," to which Rihanna responds that she judges a squad by their skills and not by where they come from. Rihanna ultimately selects Crenshaw Heights as the winners, and the Pacific Vista squad (with Britney's friend Amber as their new captain) comes forward to congratulate them. Britney and Jesse also make up, kissing backstage after their first performance. The film ends with a made-for-film music video of Rihanna's "Pon de Replay" with the Crenshaw Heights squad dancing in the background. During the end credits, the main characters are seen dancing to the outro music as the film ends.

Question: Who is Britney's nemesis?
Answer: Winnie Harper; Winnie