Hi lifewithbuns, I’m the forum leader that is bunsitting. Although his episodes involved pellets, not hay. Im grateful for that at least because it would be really hard to monitor them everytime they go to eat hay!
Some additional questions, was this also happening when you first got her?
Is it timothy hay she gets?
Does it come in a bag or box? Has it been more dusty lately?
Have you tried a different type of hay if she’s only had timothy so far?
Something to try is misting the hay with some water or even dipping in a bucket of water and shaking of the excess. This has been something some owners have done to help their buns that are particularly sensitive to dust. In doing this, you only want to offer smaller portions at a time and remove uneaten wet hay at end of day.
Recording some video of her is a good idea. It would be useful for the vet to see also.
Perhaps she need a scan to see if there is something obstructing her nasal passages?