Hi I got some info from DD but she has now gone out and I wasn't able to write it down so will post again.
Just a few thoughts tho:
DD thinks and I agree that wonderful tho Little Women and Anne of Green Gables are, they are not suitable for an 11yo. Not bc of sex or violence (!) but just the language is quite complex and the themes addressed will proabably seem remote and dull for an 11yo.
Something classic like The Secret Garden would be good tho if she hasn't read that, as that was aimed at children - whereas LW was written for (IMO) young women in their late teens (not called that then haha) and is better read by a 13-4yo who can have a better idea of the historical context and the issues rasied.
DD also said (and I really agree) that The Hunger Games is really not suitable for an 11yo. If it doesn't really disturb her, the themes will go way over her head.
In fact she suggested that rather than YA as such, which is aimed at 13+ really, she might want to look at some of the books in the children's section at a higher level. Here is where I come unstuck as I cannot recall the titles. But one thing she did say was Jacqueline Wilson – no, not all of them, but quite a few are aimed at pre-teens.
One tip was to look at the age of the protagonists – if they are roughly the age of the reader then you are on the money. If an 11yo picks up a book about a 16yo heroine, chances are it will be too old for them. The risk is not just upset over adult themes, but also "this is really boring" and being put off reading.
Will post again with some actual titles from DD (who btw is 24, and an avid reader who grew up on YA).