E.J.
would she tolerate ear plugs/buds? if so, she could wear those and they would be more discrete that headsets. My son is very sensitive to noises and he wears his ear muffs for sound ALL the time. He doesn't seem to care that anyone notices. He will even wear them when I run the blender or hair dryer.
Anyway, if she would tolerate ear plugs that might be an option. Or perhaps she wouldn't care if she wore her headset. Nobody's ever teased my son for his, but he hasn't worn them on the school bus.