Hey there, inattentive-type girl here. I had plenty of issues in high school and was long suspected of having autism (and depression/anxiety), and even thought so myself. It never really fit – I was introverted, so I just didn’t like socializing and therefore didn’t care enough to learn how to do it well, so it wasn’t an issue of fundamentally not understanding. So different causes, but superficially similar presentations.
As for issues with school, I’m not sure what INSTEP is – Google tells me it’s a special ed program, a tech enrichement program, a dance studio, etc. Is it some sort of alternative course of study? Anyhow, one issue I had at my private high school was that because no one could identify the ADHD, I was pegged as possibly autistic/having a learning disability/not actually being smart enough for this school, so I got thrown into mandatory study hall with all the dumb legacy brats. I SEETHED. I knew I was smarter than them. I resented being there and it made me want to blow everything off out of spite. Could that be why your daughter is flagrantly boycotting work in that one class?
Most of my problems were inattention and having severely underdeveloped study skills. I had a breakthrough with my chemistry teacher. I flunked a test and he had me come to office hours – he was worried that I wasn’t grasping the material, but the real problem was that I couldn’t study to save my life. We did some more one-on-one stuff and he gave me some extra time on the tests and I started getting A’s.
I know your daughter has turned down tutors, but one-on-one tutoring is really, really helpful for ADHD kids because there’s nowhere for you to drift off to and you’re being constantly directly engaged by the tutor. If the school is trying to throw a tutor at her, by god, take advantage! It will be even more helpful once she gets meds, which will help with absorbing and retaining some better study and coping skills. You’ll probably have to coax her into this, but as someone who’s been there, it’s really helpful, even if it was an affront to my pride at the time.
Also, does the school have a gym or offer individual sports? Some non-team thing like track, swimming, or fencing would be a good outlet. Exercise really helps ADHD people focus.