Would I be being unchristian?

Sa

So my fiancé and I recently got engaged and are getting married in January. My fiancé does not have a good relationship with his parents (to put things simply they neglected him and put him in unhealthy situations to the point he was removed from their custody and they now continue to demand financial aid from him). We’re much closer to his foster parents and only really have a relationship with his parents because of his younger siblings that the parents managed to regain custody of.

His parents are highly anti-vaccines and modern medicine. His mother is currently dying of cancer (if she’d gotten treatment when she was diagnosed she’d be completely fine) and is constantly ill with various viruses and bacterial infections due to her damaged immune system. Today, someone asked me what I plan to do when we have children because his family is anti-vax. I personally would not want anyone who is not vaccinated around an unvaccinated infant, especially a person that is sick constantly with infectious agents. But, I hadn’t really thought about it with respect to my future in laws.

I feel completely comfortable keeping my future in laws away from my future infants until they’re vaccinated. But, my future MIL is dying. While I don’t expect her to live long enough to see any grandchildren (my fiancé and I want to wait until I’m don’t my residency, which isn’t for another 4 years), if she did I feel conflicted about not letting her see a grandchild. On one hand I feel like a child is a gift straight for God and He has entrusted me to protect that child. So I should keep her away from my child as she could infect my baby and potentially kill them. But, on the other hand God also tells us to honour thy parents. While, my fiancé doesn’t have much of a relationship with his parents due to their actions and lack of atonement, I still think they deserve respect as his parents. So I’d want to let her see her grandchild if she has the chance.

I just don’t know what I should do. I don’t know what the Christian thing to do is. I’ve tried asking myself what would Jesus do? But I still don’t know. Is protecting my innocent child more important than one of the then commandments to honour parents?