I talk about my hubby in the interview because if I was really sick he would be the back up since someone has to be here to look after our own daughter. He actually retired last week after 40 years in the military so is here all day. Maybe he will get another job and maybe not - a few resumes out but we want to just enjoy a couple weeks of less stress. I love having him here to do simple things like put the other baby in their highchair or hand out the cups as I fill them. The rest of the time he worries about our own daughter and basically stays out of the way.
I have had the question in interviews and to me it is a red flag in the sense that as someone mentioned this is my house and my family lives here and your child is invited to spend their days with us and that includes all of us including my son who now lives in Calgary or my mom who comes in the summer and stays for 6 weeks. If the family is that unsure then a daycare centre may be a better suggestion for them. I get that it is an issue but other than asking who else is home all day that is as far as it should matter.