THis sound VERY familiar. Do you know the name of your vets? Maybe you could find it on the net and call.
This happened to Simba a while back, He breathed threw his nose. WE called our vet and the told us to put ice cube in his mouth and ice packs on him [maybe it's the heat?] All day he drank water, and threw it up.. owl after bowl. Then around 9 at night he broke put in big red bumps itching like crazy. After $140 dollars later at the Emergency Vets, he was alright. They said maybe he had bitten into a frog or get bit / stunf by something. I'm sure she'll be ok. Just pay close attention to her. Is she old?