If your husband and mother share spaces in the house, I don't think disinfectant will do anything. The disinfectant won't stop him from shedding viruses if he's infected. If they aren't sharing spaces, I don't think the disinfectant is necessary. The virus doesn't live very long on surfaces, so if it's been a few days since he's been in a space, there probably aren't any active viruses around to infect her. Caveat: I'm not an expert.