The Sisters: M.Y.O.B. (The Sisters #5)

Since Amy's been going out with John, she has become the most popular girl in the halls. But she spends so much time with her new friends that she forgets Kat, her best friend. As for her ex, Nick, he still thinks about his lost love, Amy. And the icing on the cake: Amy's mom tells her that they're moving in with her new fiancé, Francis. Aaaaargh! Help! Noooo! Gross! Even if change terrifies her, Amy must try to brave the future with style!