Smother in law

Yes, I meant smother!! I cannot stand my mother in law. She is my husbands step mother. Backstory: my husbands biological mother died several years ago. His step mother was his biological mom's best friend. She got sick and died leaving 3 boys behind. Best friend stepped in and married my husbands dad within a year of her death. She had 2 boys, whom she favored. She now has 5 grandkids and favors one over the others. The oldest is 6 and even she knows grandma hates her. My husband hates her, but tolerates her for his dad. I am currently 7 weeks pregnant with our first child and have agreed that his step mom will NOT be at the hospital. She will never hold our child, let alone babysit. Her toxicity absolutely amazes me. We do, however, want my father in law there.how do we tell them this? I dont care of she hates me, but I don't want to hurt his dads feelings..