Stepchild not vaccinated for MMR should i let hang out w/ newborn?

[stepmumSW5]

My stepchild (school age) is not vaccinated for MMR. I'm seriously worried about them hanging out with my newborn. Has anyone been through this?

@evrey she is

@Whichbitchiswitch I'm pretty sure her dog is vaccinated but not her kid

@Iesugrist the father didn't think too much about that until now that we have a baby on the way and he is very much worried, so he wants to make it Happen but with the least amount of damage to the shared parenting situation that we built with so much effort over the past few years.

He was unaware of the missing vaccines until late last year when the child started school and I saw it in the forms. He had trusted that she had given him all vaccines whilst in her care as she used to be the main custodian for the first 3 years of his life and she "was taking care of it".

Thank you all for your messages. I've asked my obgyn to write a letter and we will try the amicable way to convince her that this is not just about her son anymore but about another innocent and fragile life that's coming soon.