It might be a little bit too old for her. They are fairly violent and there are some romantic themes throughout. I know they were written for young adults, but 11 might be just a little bit young. You can usually preview the first few pages of a book on Amazon, though I'm not sure if you'd get to see enough to really decide.
I wouldn't say that the books have gratuitous violence, but the author is definitely trying to make some points about violence, war, and the impact on society and children - so not really fluffy stuff.