I think she may be sneezing. (I'm not sure what snake sneezes sound like, but I'm not sure what else it could be.) But Michelle also suggested recently that it's been a while since she's seen a vet at all, so I figured it was worth a visit regardless.
No luck finding an obvious vet, though I've discovered there's a Cornell Herpetological Society. I may ask for their advice, but was also thinking of trying to call the Cornell Vet School next.