My name is***** and I am sorry to hear that your kitty is not eating tonight.
There are a couple different things that I am wondering about-
-is she not eating the food because it is tainted in some way and she can smell the difference? Spoilage, mold, etc.
-is she not eating because she is nauseous? Could she have eating something else that is bothering her stomach?
-is she not eating because she has some metabolic disease? Kidneys, liver, pancreas, inflammatory bowels, etc.
I would recommend trying some other kind of food that you know she likes, like a fresh can of something tasty. If she still doesn't eat that, you can try giving her some Pepcid. The dose for cats is 2.5mg once daily.
If that still doesn't work, she needs to see her vet first thing Monday morning.
Does this help? What other questions do you have?