I'm going to be the odd person out and disagree. Fitting in is great, but if people aren't accepting who you are--smartypants and all--then maybe they aren't the people to fit in with.

I was her when I was a kid. And my mother encouraged my grades, no matter what. So I did my homework, and got into a gifted program where, once a week, I got to hang out with other kids who were also overachievers. And I was one of the less-bright ones in that crowd. Believe me, the dynamic you're describing doesn't go away when you get older or even into your work life. I am in college, in a professional program. I had a 4.0 until this quarter, and there is a clique of girls in my program who basically shun me because they think I'm a know-it-all (because I also have healthcare experience). I'm not, I just work hard and want to do well. And I ask questions. And participate in class. And I know that these girls will not be signing my checks once I graduate and get a job, so I try to let what they say roll off and if they want to be catty and silly, then I don't care about fitting in with them.

I know it's different in grade school and it matters more for her self esteem...but so does doing well and not "dumbing down" for other people or being someone other people want you to be. I don't know what advice to give because I don't have kids but...that is my opinion. I'm sorry you're dealing with this. I hope it all goes well.