Interesting, as my child with ADD-Inattentive still had trouble getting As in easier classes due to not turning in HW or making some silly mistakes.

You are correct that a 504 plan will probably not solve the fundamental problem of focus and doing well on tests. The first school sounds perfect to me (the one with the in-between track). My youngest is in 8th grade. He was in a math track that had them do 6-7 grade math in 2 years and HS geometry in 8th grade. He fell off the tracks a bit last year and although he understood the material, really did not grasp the material at a deep level. This showed on the tests, along with silly mistakes common to a 12yo boy.

Knowing how challenging our HS honors math is (many kids drop down) and not wanting to have a tutor for years on end, we decided to drop him a level in math. He is now in the accelerated 8th grade math, but finds it too easy. He said that while the one day per topic approach last year (probably exaggerated to some extent), he also did not need the one week per topic approach of this years class. An intermediate approach would be great.

As other have said, I would not let her make this choice. I agree (as I said above) that School C sounds like a bad choice. Hopefully, you can get her to see the problems with that school. Can you get a school counselor or a teacher to talk to her?

This is also a tough age. Hopefully, things will work out as she gets ab it older.