She was fucking John Stagliano the owner of Evil Angel who is HIV positive and hence no one wanted to work with her again (until recently). The reason why he didn't get any shit for it is because he's one of the most powerful people in porn so no one could talk shit about him. The industry just went with it, ignoring that fact that he was 1) abusing his power as a producer and fucked a talent and more importantly 2) that he was fucking a talent knowing he is HIV positive
Sheena was gone from the biz for a while, doing solo stuff. Then she started working with girls and only recently did few scenes with male performers. She's HIV negative, I think it's safe to assume, but it's fucked up how it all went down.