Going 3-4 times in an hour is way too much.
Are you sure she isn't marking?
She needs to be checked for a UTI.
Your vet may want you to bring a urine sample but it is really better if they take it. If she has one, they will put her on antibiotics.
Occasionally frequent urination can mean something more serious, like stones. If she is diagnosed with a UTI and it doesn't go away or recurs or she is diagnosed with stones, I would have her bile acids tested.
It should be a simple fix though.
