Am I overreacting?

Okay, so my mother in law is driving me crazy. I get that she's from a poor country and that she values things more than I probably do. But using a sponge for dishes than clean the windows with it as ND after that used it for the dishes again because it's not "broken" yet. Ehm no. I can't live with that. Also another time I bought new sponges and trow the old once away. She picked the old one out of the bin and placed back on the kitchen sink (it was completely dirty and probably full of gems and Bacteria) then she used the new one to clean the floor in front of the front door and placed this one back at the sink as well. I mean does she not use her brain? I'm so sorry for talking like that but I'm shocked! She could kill us with the bacteria that she is putting on our dishes. It's not only gross but irresponsible. I'm pregnant and I grew up in a clean environment, I'd probably get sick them same day. I didn't see it before and since I'm living in this house I'm constantly sick. I either have diarrhea or vomiting or I'm just feeling unwell. And now that I'm pregnant I really don't want to risk anything. But if I say something all I get is "she won't change that's how she was brought up" well I don't care. If you force me to live here so you don't lose the house than play by the rules and don't kill me.