I'd absolutely hate someone moving themselves into my house, your house is your sanctuary, your safe place, your home. For someone to just come in and just breach that must be very stressful at the best of times but during a pandemic even more so.
You've still not said what tier you are in?
I think she's being disrespected left right and centre here by everyone involved. She's made it clear she's unhappy opening her home to you so you need to leave really or its going to cause even more problems with their delicate family dynamics, if you've got somewhere else to go don't cause unnecessary trouble by staying there any longer....