What concerns me the most is she says she can't remember what she read!
A discrepancy of more than 10 between VR and NVR is indicative of a problem.
School being happy means nothing. It might mean they have very low expectations of your DD and therefore think 9th percentile is fine. :)
I think there is an underlying problem, and it's going to take you a while (and a bit of money) to sort it out. My DD has problems, and it's taken me about 3 years to get to the bottom of it.
It sounds like your DD has 'working memory' problems. There are lots of tests on Cognitive Fun you can do. Try the 'backward digit span' tests to test her working memory. If she can't do 5 digits I believe that indicates a poor working memory.
However, I'm not 100% sure what a poor working memory indicates :) I'm fairly sure that a poor working memory is still an indicator of another problem, and is not actually the problem you should be trying to fix.....
I've been reading a lot about vision problems today, and read that convergence insufficiency can cause you to not remember what you read.
Get a pencil and ask her to follow it as you move it towards her nose. Her eyes should go cross eyed as it gets close to her nose - and she should still be able to see the pencil, it shouldn't go double of blurry.
Here's a of how to do the test, and what her eyes should look like.
Also can she track an object with her eyes?
If you can afford it, I think Reading Plus looks excellent. I haven't used it yet, but my 3 are all due to start it in Jan. :)