This may sound harsh to some, but a couple of major beatings early on may have set her straight. Probably too late now for that approach.
Socialization (and lack of) is hard-wired into them at 6-8 weeks. They learn that if they bite, they may be bitten. Well socialized dogs aim to please their master. Unsocialized dogs just don’t get it. That said, I had a pit that chased invasive cats out of the yard. His cats...pack members...could, and did, sleep on him.
It is not just harsh but does not work. Creating fear through beatings just means the dog will be more likely to respond with a fight or flight instinct. Sometimes negative reinforcement may be necessary but it is done immediately and quickly.