Just something to think about, I was recently told that dd(8) reads silently faster than she can keep up with reading aloud. Her writing is also horrible, and I believe that in part it is because she thinks faster than she can write (ie, her hand can't keep up with her brain.) It sounds like your dd may have the same thing going on, ie she's trying to make her hand keep up with her brain, and that leads to sloppy handwriting. My dd also prefers typing to handwriting, again, I would assume because it's faster for her. Not a professional opinion, by any means, but might be something to chew on.
I think this is exactly right regarding my DS, too.
