Post a message or simply read what others have written and answered. Rachel, a RightStart™ Math user and one of our customer care people, will be monitoring this forum. She will respond to your questions as needed.
Have a great day and remember to play a math card game!
I hope my response is not too late here but I just wanted to help out. I'm in the same situation as you are. I have a 7yo 1st grader who reads above grade level and she is motivated to do math but she isn't ready for some of the more complicated aspects of level B right now. I have two older children in Right Start (one who is almost done with Level E and about the start Geometry and one who just started Level E) and I have a lot of experience now with homeschooling in general and Right Start math specifically.
My opinion is that it is OKAY for her to not be ready to go on yet. With my two older kids I found that in Level B in the 70s somewhere when mental trading was introducted they had to step back and take a break for a while. My 7yo has reached a "take a break" point in the 50s. (FTR, we did Level A with her when she was 6.) This has happened in almost every level of math with all of my kids and I think it's a normal developmental phase.
I have said here (and on the Yahoo Group) that I think sometimes kids need to stop learning new stuff and just let the things they already learned kind of marinate or ferment (choose your metaphor LOL) in their brains for a while. Then after a few weeks of playing math games or maybe even not doing math at all, start again and see what happens. You don't have to be "doing" a program or curriculum every moment at this age in order to be making progress. IME, the break time helps them pick up the concepts again with a fresh mind and they often easily understand things they previously didn't. And this is something that applies to all subjects in homeschooling, not just math... It's the beauty of homeschooling!!!! 
Instead of your child falling behind and being labeled "dumb" or "slow" when she can't keep up with the program, you can just take a break with no shame or guilt and she will likely advance more in the end because of it. It can be hard to break out of the "school" mentality in which the kids have to be kept busy with *something* so they may keep on doing worksheets or keep plodding through the program even if not all the kids are understanding it. If you're not "doing math" for a few weeks, it's okay.
Particularly if starting with Level B, Right Start does a really excellent and intense job of providing kids with a really great "number sense" and I would encourage you to take as much time as she needs to really get that. If she likes to do worksheets you could print some simple ones off the internet for concepts she knows well (like +1s or something easy like that) but do play the games with her and keep referring to the abacus when you do it. You can also find some math games and craft activities in the meantime if you really want to fill in your "math time" with something. I like the Math Cats website for some crafty math ideas.
I have to run now but I hope this helps.
