I'd say now is a good time to get involved, because you don't want a kiddo who decides they're not good at math, and holds herself back based on that, if there's no good reason. 75th percentile isn't average. It's above average... it's just not what you'd think a child with that IQ is capable of.
For what it's worth, my attitude was the same as hers in 2nd grade, not because I was no good at math, because it was all boring repetition, and I was prone to boneheaded mistakes. It went away when the math finally moved on from adding and subtracting increasingly larger sets of numbers.
Nowadays, elementary school math curriculum is a dog's breakfast of nonsense algorithms that only confuse and frustrate. Maybe some time at home drilling the standard algorithms will help.
