Since math is sequential you really have to start where she is, not worrying about he grade but where she is and a goal of where she wants/needs to be in the future.
We use MUS but just jumping into a level can be tricky unless you have the ground work, addition through decimals, then you could start at prealgebra. The reason jumping into MUS can be tough for levels Alpha through Zeta is that the scope and sequence of MUS is different than a lot of traditional programs. We really like it and once they finish Zeta they have a solid grounding in math to move onto Prealgebra. The upside is if the student knows addition, subtraction and division but need to start with fractions they could start in Epsilon. Or if they need worl with division start with Delta. So they can start where they are at it is just a little different.
I would suggest talking to someone with MUS directly and letting them know where your daughter is at and where she would best start if you choose MUS.
I have not use SCM math programs, but use many of their programs and really like them. They only reason I never tried it is that we started with MUS 7 years ago and it was worked so we have just kept working along. It is also not teacher intensive at all which has been a big help to me. I like math and do well, but explaining the concepts is not my gift, so the DVDs are a great help for me and my kids.
