Cats usually stop eating to tell you something is wrong. If her activity levels have changed at all, or stools are unusual, you might want to take her to the vet. Check ups never hurt.
Give her some pure milk with a gulucose biscuit,if her stomach had any problem then it will be released after eating it. Try to make her active to gain her hunger.
It may be what your trying to feed your cat or maybe she is just sick. Try can food if you don't already do that or another suggestion is babyfood. It's easier to swallow but has the nutrients that your cat should be getting.