She's the liar

Entering Brookside Academy in the sixth grade, Abby is determined to reinvent herself as a confident and popular "Abbi," but she is shocked to find out that her older sister, Sydney (eighth grade) has already crafted a new identity as the president of the "Committee," the all-powerful student organization that controls extracurricular life and rules the student body through intimidation--and inevitably the two clash, because they both know what the other is hiding, and soon they are hopelessly tangled up in the lies they have created for themselves.