One possible explanation is that many kids 8.2 yo would be in 3rd grade, therefore her age scores are compared with children who've been exposed to an additional year of classroom material.
This is what I would suspect. In second grade, many kiddos would be younger so the grade & age will reflect that depending on which scores you look at.
As for another student same age, were her scores (not percentiles) different? Then she/he may have scores more aligned to 3rd grade and/or 8 year olds.
My kiddos have not taken the Cogat, but I will say that their scores would likely be the opposite with age percentiles higher than grade because in 2nd grade they would have been 6.9 to 7.6 depending on the time of year it was given.
Make sure you consider that at 8.2, your daughters 'grade' peers could be an older 6 to mid 8. That is quite a spread!
