2 y.o. cat will not stop biting

Adopted this cat that is roughly 2 years old at this point in time. No matter what I try she will NOT stop biting my ankles/feet/arms. I have tried redirection, rewarding ideal play behavior with treats. I try to play with her at least two times a day for 15-20 minutes each session. This has been the method for the past 8 months and she has shown not a single bit of progress in her biting behavior. Recently, I have just given up and resorted to other methods that are less ideal (saying “ouch” when she bites, not moving then putting her in “time out”) but still she proceeds to bite. The vet cleared her of any issues and I even went for a second opinion and they found nothing physically wrong with her. Her environment is enriched with toys and scratchers and “cat tv” aka a window hammock and and the space is a 1br 1bath apartment.

Unfortunately looking like we will need to rehome her if the behavior continues. I can’t have a cat that attacks especially when I am planning on having a family.

Just needing to know if that’s the best decision at this point since she’s shown 0 progress. This is my first cat and my boyfriend (whom I live with) has had many cats in his life and he says he has never seen one with such insatiable bloodlust.