Jane in Bloom

I'm reading Jane in Bloom. I chose this book because i heard it was really good and i liked the cover. So far, the only things that have happened in the story is its Jane's birthday and she wants to get her ears pierced. You meet her sister, Lizzie, who is everybody's idol. But shes bulimic. On the day of Janes birthday, Lizzie eats half of janes favorite chocolate cake, and freaks out, and collapses, unconcious.