Need Advice Please

Long story short I grew up very sheltered & people didn't visit us much when I was growing up. My sister in law has recently been trying to stay the night more frequently. We live in a very small apartment. We really don't have space to accommodate her. Our apartment is structured so that you need to go through the bedroom to get the only bathroom. It's awkward & there's no privacy when she visits. I get extreme anxiety because it seems like she wants to stay the night more often. I have no problem with her visiting during the day, it's the spending the night situation that stresses me out & gives me anxiety. I'm 12 weeks pregnant & this situation is stressing me out. I've talked to my husband about it but feel like I get ignored most of the time. What would you do if you were me?