So a lot of backstory but I'll try to be brief. MIL and I don't get on. After a big argument last year where I raised the issues with her bullying me, she told me she knew she was rude/had a nasty sense of humour but it was up to me to raise it at the time as she was naturally blunt and had no intention of changing that.
My MIL and her sister turned up today while I'm off sick from work with flu symptoms - fever and vomiting among other things. It could be COVID but I can't get a test. My husband is at work all day. They force their way in, saying they are there to meet the new dog. I tell them I've got the flu and MIL responds to tell me that I look puffy and awful. They guilt trip me over the dog being away from the main room (he is still acclimatising to our household so he's not constantly mixing with the other dogs until he settles). It is worrying that they didn't know I would be home - it makes me wonder whether they regularly let themselves in to our house. The sister has keys because she has previously done jobs for us.
AIBU to not be comfortable with the easy way they are using our spare set? Feel like they are just an emergency set - not a free for all to enter the house.
Backstory - last time they let themselves in was also when I was off sick ages ago so this isn't the first time. Seems like a coincidence that they've only come round twice when my husband is at work and both times I've been home I'll unexpectedly?
I don't know whether to make an issue over this - we only have one spare set - my own mother has (over time) learned to text 5-10 minutes in advance to give some warning. I went upstairs just now and realised they walked past a pile of dirty laundry and I like my house to be clean when people come round but obviously with flu, I've not been up to it.