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

All I can seem to remember about this book is that it was a book of short stories. I read it probably six, seven years ago. One was about a group of children who killed one of their playmates by pushing her from a treehouse and the other I can recall was about a photographer who was jealous of her cousin that models and one of them breaks their ankle when they are in Greece. The cover has trees on it and someone floating on a lake, I think. Any help would be greatly appreciated, this is driving me crazy!

How to Breathe Underwater: Stories by Julie Orringer

And, yes, it's very dark, but it's one of my very favorite books of short stories!