Hi S.,
I have taught music off and on in parochial schools and remember a card one kindergartener made me, with "Congratulations" written in reverse order, with a few letters reversed as well. I asked the teacher about it, and she said many kids do one or the other or both, and eventually grow out of it. Keep working with her on it, and make sure the school does too.
Re the ADHD stuff--is it possible that she is now seeing better with her glasses, so there are so many "new" things to look at, she doesn't stick with one thing very long, and this might make her seem ADHD? Same thing might occur if her hearing improves significantly through use of a hearing aid. That's just my own guess, it has no basis from consulting a doctor or anything.
I think you may be jumping the gun a little bit, but you are wise to be concerned, especially since your brother had dyslexia. Ask the teacher what his/her thoughts are. In our district, if you ask for testing, they are supposed to complete it within a certain time frame--we didn't know this and it took forever for our now 13 yo son to get tested and help. (He has a high IQ, excellent oral vocabulary and math skills, but reading just wasn't happening--he's doing MUCH better now.)
Get used to the idea that you will have to be her advocate, tutor, cheerleader, crying towel, etc. much more so than with a so-called "normal" kid. Many teachers DO care about the kids but are over-extended, and it will be your job to make sure she gets the help she needs, through the school and/or on your own.
The Schwab Learning site was recommended to me awhile back, I'm embarrassed to say I have not visited it....
Believe me, this will be a learning experience for you!! You and your daughter will be fine, I am sure you will make good choices! ;-)
K. Z.