book for 13-year-old

I decided against The Invisible Library for my 13-year-old niece. I just don't know her well enough to be sure that this amount of violence is okay. I think I'll give it to her next year, because it is really good. So I'm looking over my shelves for a replacement gift. I thought I had a hardcover of Flora Segunda, but I can't find it, and it doesn't seem to be in print. I have hardcovers of

A Great and Terrible Beauty,
Magic or Madness, and
Shades of Milk and Honey.

The first two I read long enough ago that I can't remember how age-appropriate they are. What do you think? And which of those is the best book?

ETA: also have Shadowshaper, which is a beautiful object but a bit slight as a story.