What's the Name of That Book??? discussion

I read a book a while back, wherein there are two girls who are best friends, and later revealed to be sisters, the mother of one had an affair with the other's father. The girl who dies is named Keri, I'm pretty sure. One is a daredevil, the other not so much. The living sister smashes a bust of the dead sister shortly after the funeral, and laments that the girl "in the sunday clothes" looks nothing like the girl she really was. I cannot remember this book title!

figured it out. its called undone and has been shelved.

Undone by Brooke Taylor

Hey, Kate or other mods--this is a YA book so it may be more appropriate for the other folder. It's a good book, and for older teens, but definitely YA, IMO.