Please don't feel guilty. You did absolutely the right thing!!! The MIL IS a risk, even if she turns out to be negative in the next few days, she may still be a carrier. Their family should also understand that keeping MIL with any one is a risk. It sounds like the MIL can take care of herself - so what's the problem in staying alone? Let her stay alone. It is not worth risking others lives just because the MIL wants to live with someone. DO NOT FEEL GUILTY. You are gutsy and stood up for your parents. That's admirable. If only more people had the same guts as you, we would not have so many Covid cases today!