Cricket, I'd be inclined to look at this in terms of skills rather than academic achievement. IDEA says that schools must teach academics, but also "functional skills"-- which include paying attention, remembering where you put your papers, how to participate in groups, etc.
This is much broader than most people realize, because they're stuck on what achievement tests show. But the legal precedents are clear that "functional skills" are absolutely covered by IDEA, and if a student has deficient functional skills, that may qualify them for services even if their academic skills per se are not impaired. (You can search "functional" on the wrightslaw website to get some background on this.)
What this means is that if your DD is demonstrably lacking some functional skills, the school may be required to remediate them. Of course it helps if this shows on an achievement test, but if you have frustrated email from teachers about her spacing out or similar documentation, plus outside testing that shows deficits, you can argue that there are areas where functional skills are below those of her peers and require remediation.
Yes, this is a hard case to make for a gifted kid, but it can be done.
DeeDee
