Does she circle when she walks?
Any odd eye movement like the eyes darting from side to side or up and down?
Does she tilt her head to one side?
Thank you for the extra information.
Well it does seem like her equilibrium is off. The number one reason for this is an ear infection. Ear infections can effect the vestibular system. This is a group of nerves that controls our balance. These nerves tell our brain what is up and down in comparison to gravity. Ear infections cause inflammation and pressure on these nerves resulting in what you are seeing.
It can be easily fixed with an antibiotic. So do get her a check up with your vet to get her ears looked at. This problem can cause nausea. You can give her a 1/2 tablet of Pepcid AC to help the nausea.
If she isn't eating, it is important that you get nourishment in her though. Cats can not go without eating long as it causes liver impairment very quickly.
Feed her some baby food. Use chicken flavored or any flavor you know she would like. Make sure there are no onions or garlic in it. Water it down and use a medicine dropper to feed her 1 dropper full every 15 minutes for an hour. Repeat every couple hours. Get some unflavored pedialyte and use the medicine dropper to give her 2 dropper fulls after the baby food. The pedialyte will hydrate her properly and restore her electrolytes as well.