I'm going to offer a perspective which is based on much the same observations as aeh's-- that is, no, I suspect that this course is not "too hard" at least in terms of the actual content and pacing.
My guess is that the organizational challenges are the issue-- and that the relentless pacing of an AP course is a factor.
As for the business of needing a full year of a high school subject PRIOR to the AP course--
hogwash. I say that as someone whose child breezed through a number of them and the only one that was
laughably easy was the one that she nominally had the "prerequisite" course for, although it was also not at all clear to either one of us what good that prerequisite actually did in terms of the class (APUSH).
On the other hand, the output demands of an AP course can come as quite the shock.
I don't know your child, Ivy, but what I will say is that allowing DD to "quit" when the opportunity existed to hot-house her through something that would have been entirely appropriate but for major asynchrony issues, well... that was one of our chief means of fighting perfectionism.
Allowing her to back away from challenges when they felt indimidating was one of the worst things that we ever did. We did allow it for a short time when she was about 7-10yo. It was a mistake.
Being able to tackle challenges to expand that proximal zone was
crucial in preparing DD for college entry.
It's an odd kind of developmental arc, for sure-- but this
is the developmental arc for a number of HG+ kids-- early matriculation, I mean.
