My daughter is a mature, thoughtful 10 year old. She said she liked the movie, though she found it dark and disturbing. I agreed and wished we had waited til she was a bit older to see it. We have always avoided any violence in movies, so this had a strong affect on her.
Overall, a worthwhile movie with powerful messages about "family" dynamics, anger, regret, jealousy, love, ...I think we'll be discussing and interpreting this movie for some time to come.