The route to supportive services for a 2e kid is very state/local ed. authority-dependent. Federal law certainly leaves plenty of space to qualify a gifted student working at grade level as special needs, but states have made different decisions about how they will qualify students. Go to the state DOE website and look up the eligibility guidelines for special education/IEPs/504s. Keep in mind that it may even differ by the school district. And, beyond that, your local administrators may be in ignorance of their own state and local criteria, as it is likely that they rarely encounter this situation.
Some possible routes to eligibility: aptitude-achievement discrepancy formula (easiest to use for 2e children), pattern of strengths and weaknesses (PSW) formula, RTI inadequate progress (failure to make a year's growth in a year's time, regardless of starting point--requires progress monitoring data). These are key words that you should keep an eye out for in the SPED regs of your state.
