It's always correct. So... we have about several weeks left according to the Bigger guide, but I'm not thinking it will take us that long. I guess I'll be ordering 3A for her pretty soon to make sure it's here when she finishes 2B. My concern I guess is the pace she's flying. Do I keep letting her go this pace? She has honestly never been challenged with math and with other things she tends to balk when she's challenged, so I honestly think it's probably good for her to be challenged some. She does tend to think that if something doesn't come easily the first time then she shouldn't mess with doing it. I'm just a little concerned that if she continues like this that we'll be to pre-Algebra WAY too early. I'm also worried about this "brick wall" I've heard about - that kids reach this point where they just don't have the reasoning skills available to be able to do the higher level thinking that pre-Algebra and Algebra require. Should I be concerned about that? Or should we just keep going at her pace? I know there's an awful long time between where we are and pre-Algebra. I've also just heard that Singapore is about a half a grade advanced so that means when we finish 3A she would be about the equivalent of finishing 3rd grade math? Oh, and she's fine with math facts. She knows all the mutliplication and division facts that we've learned so far with Singapore (2s, 3s, 4s, 5s, 10s, and she can figure out the rest when she thinks about it). And she can add and subtract very quickly in her head. She had absolutely no problems learning to add and subtract money recently. Oh-C is 7 and would be in 1st grade in ps, but we've always counted her as the next grade higher since that's more what she seems like and she only misses the "cut-off date" for that grade by a month.
I am not an expert but this is what I would consider doing. First I'd pinch myself just to be sure I had a child who loved math THAT much 
Then I would consider supplementing her with some of Singapore's extras. She is obviously loving math and up to the challenge. Look at Singapore Intensive Practice and Challenging Word Problems books. It has been recommended to me on a few occasions to choose the IP and CWP books half to one year behind where she is at with her regular SP math. So if she is nearing the end of 2B consider CWP 1 or IP 1B (or perhaps 2A). I have heard, though I have not used these materials yet, that they are quite challenging and progress fairly quickly in challenge, esp. the CWPs. 
) and then I'll see about starting one of those extras in 2A as we start 3A for her actual math. Then I can alternate days - one day "extras," one day "regular" lesson. Great!!! That helps SOOOO much. Maybe I can spread things out a little bit that way.