Elsewhere by Gabrielle Zevin

Welcome to Elsewhere. It is warm, with a breeze, and the beaches are beautiful. It's quiet and peaceful. You can't get sick, and you can't get older. In Elsewhere, death is only the beginning...

Elsewhere is where fifteen-year-old Liz Hall ends up, after she is killed in a hit-and-run accident. It is a place very like Earth, yet completely different. Here Liz will age backwards from the day of her death until she becomes a baby again and returns to Earth. But Liz wants to turn sixteen, not fourteen again. She wants to get her driving licence. She wants to graduate from high school and go to college. She doesn't want to get to know a grandmother she's never met before and have to make all new friends.

How can Liz let go of the only life she has ever known and embrace a new one? Or is it possible that a life lived in reverse is no different from a life lived forward?