Third hand smoking? Advice?

Cierra💙

So here’s the run down, I’m 14 1/2 weeks pregnant. My husband is deployed currently. My MIL is staying at my house bc she has no where to go. She doesn’t smoke near me but I’ve been reading that third hand smoking is dangerous for my unborn son and I’m FREAKING out. I don’t know what to do. I noticed the smell of smoke when she first moved in but I guess I got used to it and don’t notice now? Anyways, my mom came over and told me she smelled smoke really bad and that my MIL “was certainly smoking in the house”.... I feel so conflicted bc she has no where to go but I don’t wanna endanger my son for anything.