I would suggest taking her to a vet to see if there may be some underlying issue. My cats have been on a "diet" for almost a year and actually gained weight. After speaking with their vet, she suggested I switch them to a diet specific food--they are now on Science Diet RD. She also told me that I was still feeding them too much; they've been cut from a 1/2 cup each/day to a 1/4 cup/day. They still get treats but not as often, and I'm trying to play with them at least half an hour-hour each day. Good luck!