Thank you all for the advice and resources! We are now seriously considering a grade skip (and all of the pros and cons there).
It may be complicated since the grade 3-5 gifted classes require additional testing, which has already taken place for next year. But even if we have to wait a year for that gifted program, a regular third grade classroom may be a better fit than second grade.
Our daughter is surprising us outside of math as well. For example, she has been enjoying reading some series at guided reading level M, so we assumed that was about her level (though her previous school evaluation was at level J). But then yesterday she found a book at level S that looked interesting and devoured it with no issues. So I get the feeling there is a lot we don't know about her abilities.
