I'm a 13-year-old girl, and I watched this movie right after finishing the book in two days, after not being able to put it down.
I see how it might not be suitable for some people, and I'm not just speaking about children here, but to me, this movie had a great impact.
I used to laugh and joke about paedophiles and murder/rape cases, but this movie opened my eyes. It just seemed so real. Though you didn't see her get raped and murdered, if you read the book you could picture it all in your head. The surrealness of her family eating dinner while she was in agony, dying all alone, is something that places quite a heavy weight on the reader/watcher.
In terms of sexual references, there's pretty much nothing in this movie. The only way to tell that she was raped was if you read the book.
A young child can't understand this stuff, but I don't consider myself a young child. I'm 13, and I'm well old enough to watch and read this type of thing.
The violence is a bit confronting, but it's the surroundings, and the atmosphere, that really put it out there. It's done splendidly and beautifully, and I think the special effects were done as best as possible.
Kids my age, we lie in bed and wonder about what comes after death. This movie didn't clear anything up, but instead it showed me that life is too precious and pure to be gone after death. From now, my relationship with my family is more cherished. You may say it's just a movie, but it was as if I was experiencing reality itself. Everything just had the right amount of unfairness and despair for it to be reality.
Overall, I highly recommend this movie (and the book) for those who want a highly moving experience that will have them in tears and enlightenment.