Oh gosh, this problem is so familiar to me! My DD age 10 has the same Lexile range as a high school junior. She is also very into fantasy like your daughter.
We keep heading to the Young Adult section of the library, and because fantasy seems to keep to pretty safe themes (though there can be a lot of violence which never troubled my daughter even when she was three), we are getting as many fantasy novels as possible. DD is almost through the Warrior series, and thank the Lord, appears to want to move onto the Seekers series next.
Okay, I have a few suggestions. Try to find a great series, or a prolific author, because that will save you a bit of time (we all know how quickly our HG kids devour books.)
Did you try the recent offerings from the British Isles? Perhaps the different perspective and different way of phrasing things might appeal to your daughter. I do remember from my childhood in Britain that books for children are revered over there, not to imply that they're not over here! Try browsing a bit on a current mum's website that discusses books.
Continuing in that vein, I bet there are some great foreign (German, French, Japanese etc.) translations of books that might be age-appropriate.
What are some current classics at the college level? Jack London, Nathaniel Hawthorne etc. are authors that come to mind. They can't be too racy, can they?
And finally there are the good old non-fiction offerings! I'm thinking of Ralph Waldo Emerson, Thoreau etc. not to mention all those lovely science and history books in the library. You'd have control over the subject matter, and your daughter might really enjoy them.
Let me know what works! I'm right behind you in terms of where my daughter needs to go, and I've been thinking about this issue, too!
