I loved this book. It was perhaps a little slow-moving and grim at times, but the reality of the situation must be grimmer even. The seemingly clever moral situation Anna is faced with - saving her sister or keeping control of her body - is actually nothing to do with her, but her sister.
Spoiler
But the ending? I was intrigued as to what decision would emerge from the situation - would Anna donate the kidney, or not? More importantly, would Kate accept it? Then, conveniently, Anna was in a car crash rendering her brain dead, a perfect candidate to donate that kidney to her sister. No decision; it was made for her. I suppose the irony and circular storyline of this - that she was conceived to save her sister, and having done this she died - is neat. I just personally didn't enjoy this - it was a cop-out. This family, already fighting a long-term battle for a daughter with severe cancer, also has an arsonist son and now a daughter dead in a car crash. How much misfortune can five people suffer?
This ending didn't ruin the book for me, though. Just made it all seem rather more tenuous and less realistic.