She is probably allergic to something. Get her on good canned food
(meat as the first ingredient, no wheat gluten or corn) and give her
2 mgs of Chlortrimeton every 12 hours, just the allergy kind, not
the "D" or decongestant kind. See thread above, "I have a question."

Also, cats do this if they are upset about something. I had a cat that
was going bald (your cat is likely licking the fur of her belly etc) until I
figured out why she was overgrooming. (My other cat had started
invading her turf every night, sleeping on her bed. I stopped that by
visiting with the other cat downstairs, voila, no more overgrooming,
fur grew back in.)

P.S. My cat also gets the Depo Medrol shots, and you are wise to
keep them to a minimum, they have bad side effects when used too
much--like diabetes.

does not have parasites like giardia or cryptosporidium?