I enjoyed reading this book. We know from the outset that it's about a girl whose twin sister has cancer, but this isn't quite like other books which focus on a disease or tragedy. 
 (view spoiler)[I love that the book does not end with Jena's death. It leaves it open-ended, so that we can imagine her surviving or not - it's up to us. Plus, I think it changes the focus of the book. We shouldn't be worried about death, we should be working on living. (hide spoiler)]