The way to tell if it's fleas is to comb her. Any "black dots" that are moving are fleas. Any black dots that aren't moving is flea dirt (flea eggs). I'd also take her to the vet.

My cats had fleas recently. Fortunately, I caught it early enough where 2 applications of Revolution did the trick. The problem with fleas is once they get in your house, they multiply and are even more difficult to get rid of.

Good luck.