step child & shots

Sindy
So for the past 2 years my husband and I have been telling the mother of his child to please take his daughter to get her physical and get up to date with her shots & if she doesn't find the time to please let us know and we can take her. I'm now due in 3 weeks, and this child who is turning 4 in December still has not gotten up to date with her shots & for sure hasn't gotten her flu shot. I'm sorry but I'm not okay with a child who's not vaccinated to be around our newborn baby, she's gotten my husband, 2 other kids, and I sick before when she has came over. Today my husband texted her and asked her if she has gotten them & if not that he's willing to take her and she FLIPPED OUT saying that she's a good mom and that her daughter is in good hands etc etc but none of that has anything to do with vaccines!!!!!!! We don't even know what doctor she takes her to now since she hasn't taken her in forever and changed her pediatrician who she hasn't even taken her daughter to, and it's not like we can take her to a random pediatrician because we don't even know what shots she's missing. What say do I have in this??? I know my husband will be upset if I tell him that his daughter can't come until she's been vaccinated because that might never happen either way smh. Suggestions?
PS: The mother is not against vaccines at all, she's just "too busy & going through issues" & that's why the child has not been taken! Before you're quick to judge me let me ALSO add that the little girl's mother is an ESCORT!! It's already bad enough that she has gave her daughter candida in the mouth by kissing her child in the mouth after she does nasty things with men. So not only do I have to worry about the little girl spreading germs through saliva, I also have to be worried about the child not being vaccinated!!!!!