It's not uncommon to see them react like this after vaccines, particularly if they get a rabies vaccine. If she feels warm to you, you can take her temp with a rectal thermometer. Normal resting temp is 101-102.5.
I would try and get her to eat SOMETHING, even if it's just a small piece of chopped chicken.
If she's not eating or drinking by tomorrow, give your vet a call because cats can quickly go downhill when deprived of food.
Let me know if you still have questions.
