Thank you both for your replies. Unfortunately, going without a supplement in math is not an option. Before Aleks, she was not progressing and the teacher said that she was "struggling." After Aleks, doing it a few times a week for 20 minutes at a time, she was getting top scores. Huge difference. When I say she "checks out" at school, she absolutely does. It's easy for her to pass and she has no motivation based on grades. She has done fine on the curricula in school even with spending just a few hours on Aleks sporadically over the past year, so perhaps she is over whatever was making her struggle previously, but I am not willing to risk that at this point.
I guess more of the question was can a kid skip Pre-Alg and still do fine in Alg and Geometry and particularly in Aleks because it is a program that can add blocks of topics based on lack of mastery indicated on the assessment tests given. I will contact Aleks and find that out - I just hadn't thought to ask them about that specifically. They say to advance at 85% and to go back if they assess at less than 15%, but I don't want her to miss any blocks of info, right? So, actually, this is a question that I should be asking Aleks, of course. That makes sense. Sometimes I just have to verbalize a problem before answering it myself.
As for AoPS, it explains the whys of the math, which, from what I have seen, is not really provided in the standard-issue school curricula. I am thinking that the problem solving aspect will engage her and challenge her. I do not trust that the math courses will be sufficient for her. I don't want her to be able to do the math but never understand it, especially since she is not a mathy kid that plays with numbers and instinctively decodes mathematical language.
I should qualify, I hated math as a kid - was allowed to drop out of math essentially in middle school, barely passed Alg I in HS, took "consumer math" and graduated with that. I had to work through basic math and the entire Alegbra progression in college, finally getting some pre-calc at a community college when I was in grad school to cover some things I needed for an engineering management course. I know we are not supposed to project on to our kids, but I want her to have the opportunity to enjoy math. I do now that I "get" some things that were never taught. I am not looking to hyper accelerate her or anything, just engage and challenge her, just as if she was not a natural reader and needed a nudge to read at a more challenging level.