I think you daughter would likely be just fine in the class, so long as she's able to comfortably keep up in the PreA classes.
My dd took the PreA classes when she was very young, and although she did fine with them, I wanted her to go slower and be 100% on the PreA materials before moving on, so i actually had her re-do the book after the classes. (When she took the classes, not all the text work was assigned . . . I had her redo the books doing 100% of the problem sets.) So, anyway, if you're not in that sort of position with the courses, then carry on, and I'm sure she'll do fine.
One small trick I had when my kids took AoPS classes was to have them start the first couple chapters before class began, so they'd have a jump start, which bought them just a little flexibility once classes began. (Although, truth be told, their head start never lasted more than a couple weeks.)
For my youngest dd, who did AoPS from PreA, she's never slowed down or ran into trouble with the AoPS materials (PreA -- 4th - 5th, Beg. Algebra -- 6th & 7th, C&P, Geo - 8th gr, so far). I think the PreA gives them such a good foundation that, at least so far, none of the subsequent books are difficult. We're taking it year by year.
Personally, I wouldn't try AoPS from a different provider if AoPS courses themselves have been a good fit. I don't think you're likely to find better teachers or peers than AoPS provides -- for a gifted math student who can keep up, that is.
My youngest hasn't taken AoPS *courses* since PreA, because she hasn't needed the teaching and we like to control the pace, in particular to make sure of mastery before moving on, so I didn't like not having time to work ALL the problems. She might take an AoPS course sometime soon, as I'm keeping that in mind as we approach materials I won't be able to easily jump in and help on the *very rare* occasion it's needed. If she keeps being able to self-teach no problem, then we'll be fine, but otherwise, we'll consider a class when we need it -- for access to a teacher.