Irksome mother in law

My recommendations would be:

1. Talking to your doctor in order to make an informed decision about getting vaccinated or not.

2. Finding another place to live that's not with your MIL.

Of course it's up to you whether you want to get vaccinated, but right now, you're a guest in your MIL's home. I would personally never allow an adult who refused to get vaccinated to live in my home, but that's just me... If you want to tell her to back off, my recommendation would be to find somewhere else to live first. It sounds like she is causing you stress anyway, so it would be better if you lived elsewhere

I second ALL of this. But also, I would caution you against using language about your future MIL, especially since she is letting you live with her: "she’s like a lonely bitter dog with a bone." If you want to salvage your relationship with her, you will need to be a lot kinder.

OK. Sounds like moving out will solve most of your problems. Good luck gaining your independence!

I understand that it's scary to think about unknowns, but I'm going to agree with all the others on here who have advised you to talk to your doctor. As someone who had Covid-19, I can assure you that it's not something you want. FH and I both had it last fall and it was miserable. He had a fever over 104 for days, at points he was actually delirious and it was really scary to see the man I love be so sick he was literally out of his mind. Also remember, you need to weigh the risk of possibly being pregnant and then getting Covid and how dangerous that could be. Best of luck with your FMIL.