Oh, and I seem to recall that the Menolly (Pern Harper Hall) novels also have a subtext alluding to a romantic relationship between the very young Menolly and the much older Masterharper.
I read all the original Dragonrider and Dragonsong novels when I was about nine and ten, and, I think, just ignored anything that didn't make sense in my experience, which still left enough for a good read.
I second Watership Down. The Plague Dogs, also by Richard Adams, is also good, but a bit heavier for a tween (though I read it at about 12).
Another author:
Zilpha Keatley Snyder--The Changeling, Greensky trilogy, many others.
I also read Roger Zelazny's Chronicles of Amber at around this age. Someone else may recall if there is a lot of potentially age-inappropriate material in it.
Oh, and T. H. White's The Once and Future King trilogy. The original "The Sword in the Stone" was quite child-friendly. The revision, which appears to be the canonical version nowadays, is a bit darker.
My tween loved Roger Lancelyn Green's classic re-tellings of "King Arthur and the Knights of the Round Table" and "Robin Hood".
Last edited by aeh; 08/28/15 08:54 PM.