Hi, I am Dr. Peter and would like to help.
1- Does she carry her head down?
2- How long has this been going on?
3- Is she drinking more then usual?
This symptom is typical when cats have low potassium (hypokalemia). This is very serious as they can die if untreated. It usually happens as a result of kidney disease. Walking around in circles is probably a symptom secondary to whatever has caused her potassium to be low. Unfortunately, this case truly needs a veterinarian. If you can not have her seen by a vet the only thing you could do is supplement her with pedialyte which has potassium in it; but, the underlying cause has not been addressed and she will probably continue to be hypokalemic.
If you have additional questions I will be glad to answer them.
It is not curable but it is treatable. If she is in complete renal failure, then putting her to sleep in an option.
For the rest of her life.