Yes, she is a high achiever, that is just what I would call her. Our school uses CogAT to qualify kids for the TAG program. So it is technically a gifted program, we just got the news that she was in it about a month ago. They test all second graders here with CogAt. I only know her IQ score because her and I volunteered at a research study at a medical school, and part of it for her was an IQ test which they told me the results to.
So, are you saying that her IQ score was average but her CogAT score was in the upper 90s? That is interesting if so. I am not a big fan of groups tests like the CogAT for GT ids and have seen some kids who test highly on them who don't seem gifted (and the reverse, kids with high IQ scores who don't test in the GT area on the CogAT). However, scores can also fluctate on ability tests more than I thought they might over time. If her IQ was tested at a really young age, it might have been a less than accurate result.
I do get where you are coming from, though, about thinking of gifted as a different way to think more so than high achievement and I do think that is an accurate assessment. I think that schools much too often confuse achievement with gifted thinking. That is another reason that I'm not totally fond on using tests like the CogAT for GT identifications b/c they are multiple choice and rely pretty heavily on fast, convergent thinking. If you see an out of the box answer rather than what the person who wrote it intended, you tend not to do as well. Finding kids who think within the box isn't a good way to look for giftedness IMHO.