I've noticed that while many readers automatically read left to right, there are others who see the whole word or sentence at once, which slows them down (especially reading out loud). You might try getting single line reading window (if you have a local education supply store they'll probably have one) and cut it to the size of 1 to 2 words. Teach your dd to slide it across the page as she reads. If this is the issue, she'll be able to fade it out after awhile because her eyes will pick up that pattern of tracking. Or...try different colored overlays. Some people have a strong preference for seeing the text against a background that is a color other than white. A final idea: check out a large print version of a book she would like to read. See if she finds it more enjoyable to read when the page is less visually cluttered. This sounds similar to students who are able to spin lengthy and detailed oral stories but who balk at writing them down because the physical act of writing feels slow and cumbersome. If you can take the cumbersomeness out of the physical act of reading, maybe her enjoyment will come to match her ability.