Hi,
Sounds a bit like my son. He wasn't diagnosed with ADD, but did have trouble processing symbols--but oddly enough, only letters--he has always been great at math. He has always had a great spoken vocabulary but struggled with reading, and I knew he was way too intelligent to be getting scores near the 17th percentile for reading (in grade 2).
What helped him was a tutor who sat with him during class (sometimes pulled him out but mostly was in class) and helped him focus. He had an IEP (Individualized Education Plan) until 9th grade, when it was discontinued due to no longer having evidence of disability--he was on Honor Roll with mostly As and one or 2 Bs. In grade 8 the plan was "observation only", so he was actually only really getting services in grades 3-7. So some things can be learned, and there is a definite hope for maturation helping out here. Is your dd among the younger students in the class? just curious.
You are fortunate that the teahcer is so helpful.
As a teacher, I have taught a couple ADD kids on meds and I had no idea they were ADD, I found them delightful.
I would also recommend reading the book "Is This Your Child?" by Doris Rapp, MD. It's about allergies and the changes that can occur when you remove the offending substance. If you go the allergy route, I would suggest you being keeping a food/mood log; also, if you suspect sensitivity to environmental stuff (dust, mold, carpet adhesive, chalk, perfume) include those as well. The doctor may ask you to keep a log, plus you may find some insights from it yourself.
Best of luck to you!
K. Z.