You can't be serious.
I would not want her anywhere near my home. Why should YOU employ her after she's slept with your boyfriend/husband? (you didn't specify) You shouldn't have to put up with having to know she's on your property everyday. No way in hell would I put up with that B coming to my home and taking money out of my bank account (his bank account) and smoozing up with him while I'm laying in bed sick.
Maybe that's just me. I don't know. I wouldn't stand for it. I'd demand that she get the heck off my property permenantly.
If he's really sorry, he would have fired her and found somebody else to work for you to make you feel more comfortable. Keeping her there is unbelievable to me.