Random question about cats and newborns.

Monika🎀

Completely random but I just want to get other moms opinions on this. My mother in law has no joke 20 cats that live inside of her 1500 sq ft house. She keeps telling us that she cannot wait to watch our newborn son when he comes.... I do not know for sure if being in a home with that many cats will harm my baby? My husband and I have already agreed to not let her watch him at her home. I just don’t know how to break it to her. Could that many cats and the smell potentially hurt or make our son sick? If anyone has any advice I’d really appreciate it. T minus 3 1/2 months to break the news to her 🤦🏼‍♀️😳😐