DD doesn't present as "typical" ADHD, either, and neither did I, which is why I had a late diagnosis and recognized some of the same behaviors. Other than the disorganization, and the occasional disruptive comment in class, there has never been any indication at school that DD had ADHD, and I'm pretty sure they thought I was nuts when we started treatment.
There has never been any question that DD is bright, every PTC is all praise for her high scores, but she's never been pushed to see where she can go. This year they changed her math level placement like 4 times because she kept testing above grade level, but then her actual math grade was all over the place with missing assignments, etc. Finally, during last quarter, the teacher let her move ahead at her own pace and she whipped through everything with A's for the rest of the year. I know she doesn't perform anywhere near her level of capability, but no one cares because she generally has A's and her test scores are high.
She's never been perceived as having a behavior problem, and because she is socially adept she she often sought out to partner with kids who struggle. But privately, she has a serious attitude problem that is quickly slipping out of control, and it is directed towards school. She's much more sarcastic, her respect for authority has declined, and she sees her teachers as not really knowing anything. Aside from her lack of organization, which is more obvious the more independent the kids are expected to be, and the occasional impulsive comment in class, I doubt anyone outside of our family would even be concerned. The change in her attitude and frustration level to those who know her is alarming. I tried to attribute this to hormones and moodiness, because she did hit puberty early, but especially since she has been out of school for the summer and is doing much better, I don't think that's a reasonable explanation.
I really thought we'd be able to get her help without the full blown private evaluation, but it's clear that's not realistic, so I'm heading in that direction. Hopefully the school will work with us as the new year starts and we are sorting everything out.
