We have a great online Maths program here, it's based in Australia I think but could have branched out to the US by now. I hope it has. We've been told that it fits in with the Aussie/NSW curriculum, but if they've branched out as I hope they have, they should have adapted it to also fit other countries' requirements.
I'm not telling you to use this particular package, only that they exist. If you can't find one specifically for the US curriculum requirements, then try ours. The kids have the chance to compete (if they want to) with kids from other countries. It also gives you, the parent (or teacher) feedback on how they're going and keeps track of problems. In Australia there is a help line where the kid can talk to a teacher/tutor over the phone if they want. So whatever you find - make sure it is at least this good and no more expensive.
Don't pay a fortune for Maths computer tutoring - we compared a certain very famous and very expensive computer tutor system (which shall remain nameless to avoid lawsuits) and found this one was just as good if not better.
The cost to us - A$99 a year per student. You can change the grade through the year if you feel you need to. It DOES need a fairly recent internet access program to use it well (we use Firefox) and ideally you should be on broadband.
We actually don't use it as much as we'd like - difficult child 3 is a correspondence student and we signed him up when this was partly the way his school was giving him work. However, the school have dropped it now (pity - a lot of teachers wanted it continued) and I'm thinking of talking to his maths teacher to find a way to incorporate this with the correspondence work he does.
But I'd still sign him up with it - the computer is a non-judgemental way to study.
There is another related computer-based education package with this mob, sometimes you can get both for only a fraction more. But if it's spelling, and they don't have US option, I'd leave it. There are too many differences.
I'm glad you've made this decision. How does she feel about it?
Marg