Hmm... my two sneeze occasionally but generally only when they put their noses into dust or sneak into the bathroom when there is talc going around!

Not sure about cat allergies; my parents have a labrador cross who suffers from skin allergies in the summer so it's not unknown for animals to have problems.

I wonder if your cat has got some sort or irritant in her nose; I don't think she should be sneezing so much. I would get her checked out by the vet.