"Stupid, if you think about it, cause ADHD and anxiety aren’t like a cold; they don’t come and go with changing wind storms. You have it forever! "
Not true, in our experience. Really depends on the situation. My son was diagnosed with ADHD, and the diagnosis was confirmed, then later refuted, by multiple doctors. Turns out he has another disorder that was leading to ADHD symptoms but rarer. Anxiety I’d be more likely to believe is forever. My other son was dx’d with autism, and he is still considered on the spectrum but I do not know if he would be diagnosed as such if he was evaluated de novo right now.
My son got an accommodation for a single; the school sounds like they are being extremely unfair to the OP’s daughter. Would your state’s, or California’s, protection and advocacy agency be a good place to contact? We had a lot of success with them on education issues.