Does your daughter go to my school? That sounds very familiar. Anyway…
If I told someone about serious problems in my life and their first reaction was to feel burdened, I’d question whether I was choosing the right friends. I don’t know her friends, but if they’re like most people they’d hate nothing more than for your D to suffer in silence when they could’ve helped.
As for the core issue: it may be that sunlight is the best disinfectant in this case. The school is happy to treat your daughter like a second-class citizen when everything is private; what would they do if the next issue of a local paper read “XXXX School suspends straight-A student due to disability?” Is her disability advocate in contact with higher levels of an organization (city/statewide)? That’s another way to prove there is such a thing as bad press.
Your daughter is what Supreme Court lawyers might call a “model plaintiff.” She did her due diligence, earned straight A’s, came to an agreement with teachers to complete work in her own time when she wasn’t in school, etc. The school appears to have made a choice that benefits nobody, out of muleheaded adherence to the rules or because an administrator spilled coffee on his/her lap and decided to ruin someone else’s day. That puts you in a much stronger position than a string of D’s and discipline issues would. If this story is widely publicized, there’s no way it’ll be good PR for the school. You should make them aware of that fact.