In-law woes

Can anyone give me some good advice on setting boundaries with my in laws? My husband doesn’t have a good relationship with his dad and he really doesn’t like his step-mom.

They’ve recently decided that they are “entitled to having the baby one whole day a week” and would like us to choose a full day for them that will be scheduled each week. His step mom even said she wants this to begin the week after I deliver because i “only need a week to heal, right?” I don’t feel comfortable with this for a plethora of reasons (I’m not completely comfortable around his dad after several instances of inappropriate behavior/comments. His two step sisters have behavioral problems that escalate so fast and dramatically that I question my child’s safety if they’re left alone with her. Among others.) I just don’t know how to tell them I’m not interested in them having her once a week without me there - or at all. I’m totally cool with his mom or either set of his grandparents. Just not his dad and step-mom...