MIL is anti vax need advice

Catherine

So my last pregnancy ended in my daughter being born at 35 weeks with me having having a c-section . We knew that my MIL was not going to get a TDAP booster because she was battling breast cancer but is also anti vax. I’m currently 24 weeks pregnant with our second child. This time my child will hopefully be born in the middle of March, which is prime whooping cough season. I know I will need a c-section again and that I will need help during the recovery. My mom will come for a few days but can’t stay for an extended period of time. And if the baby is a preemie, then my husband will go back to work until the baby is out of he NICU. I want to ask her again to get the TDAP vaccine since she’ll be around the house so much. And if she doesn’t I think I need to tell her that I won’t be asking her for help for them sake of my child’s health. I’m worried that I’m going to make drama in the family and cause friction. Any advice as to how to talk to her about it? If you have dealt with this how did you deal with an anti vax family member? Thanks