Style. Sabotage. Sisterhood. When Cate and Andie Sloane's Upper East Side dad met Stella and Lola Childs's British-model mom, nobody thought a transatlantic relationship would last. But then their parents drop the M-bomb--marriage--and it looks like Cate, Andie, Stella, and Lola are going to be one big happy family. Well, big anyway. Meet: Cate Sloane: She dominates the ninth grade at exclusive Ashton Prep. Tantrum-prone and competitive, Cate would...