Hello everyone. Yesterday my sister-in-law arrived, she had a cough an…

Hello everyone. Yesterday my sister-in-law arrived, she had a cough and runny nose, and we have a one-month-old baby at home, and yesterday I noticed that the baby's voice changed, he coughs, and is restless, how can I help the child, and how can I explain to the husband's relatives so they don't come when they are sick? To my relatives, I can say openly, do you understand that when you talk, they won't come when they are sick, they will understand anyway.