Sick Christmas?

What do you mommas think? One side of my family is supposed to have our Christmas tonight. My sisters mother in law was sick last week and we are going to her house. I asked my sister she said she just had a cold. No fever or anything. I am hesitant to bring my 9 week old. I have no problem staying home, but obviously would like to be there. Do you think it’s safe to bring him if she had a cold last week? I’ve been told she disinfected the house cause she knew we were coming. But still I feel like you can never be too safe when it comes to our babies !