Welcome! So sorry we didn't see this hiding in the new posts.
Your DD certainly sounds like she has very diverse learning skills. There isn't enough information in what you've listed to suggest whether she is GT of any description. Perhaps if you are willing to share the subtest scores from the WISC and the WIAT subtest scores, it may be easier to offer some feedback. (If not comfortable posting publicly, feel free to pm me, and we can discuss further.)
Typically, apparent overachievement does indicate low assessment of ability, but it depends a bit on what type of achievement it is, and how one is determining that it is significantly discrepant.
