Is it full day or half day Kindergarten? Either way I would say something to the teacher, but my approach might vary depending on whether it was full or half. With half, you have plenty of time to afterschool.
One thing I found with the K (and to some extent 1st) curriculum in math was that it covered some things that I didn't think about. My DS could do long addition and sub. in K, as well as understanding square roots, squares, easy division, mult. etc. However, he had some gaps in some areas in K (e.g.,telling time). He is now in 4th accelerated in math to 7th, but most math in K is fun enough that I wouldn't be too worried about it until the next year, and it does help form strong number sense. Number sense is important. For example, my DD who is now in 1st can do some math work that is 2-3 years ahead, but she lacks the same number sense and intuitiveness that my DS had (she is strong in math, but her extreme strengths are in other areas). I would not feel confident pushing her ahead a year at this point, although it may be called for next year.
But, you should bring it up with the teacher either way - bring in some of the sheets she has done and ask the teacher how you can both work to keep her challenged. Why not?
