Unvaccinated friends

I know this is a touchy subject but I just wanted to get some opinions. I made friends with a lady at the park right at the beginning of my pregnancy. Her 2 kids are the same age as my daughter and they all get along beautifully. She’s been having a rough time recently and I’ve been someone she has really been leaning on for support. She casually let it slip about a month ago that she’s anti vax so her kids aren’t vaccinated for anything.

Her older child just started school and I wasn’t really worried about it because my daughter is fully vaccinated. However, now she’s talking about us hanging out with my new baby and since it will be cold it would all be indoors. She wants me to bring the baby to her kids’ combined birthday party planned for January that will be held in a chucky cheese type place. I told my husband all this and he said under no circumstances should I allow her or her kids near our new baby until he starts being able to be vaccinated. I had to work hard to convince him to at least let me take our older daughter to the birthday party and he can stay home with the baby. A family friend just had their new baby contract measles and almost died in the hospital so my family 100% agrees with my husband.

This friend is so emotionally fragile right now that I don’t really know how to tell her to stay away for 4-6 months. Despite having drastically different opinions about many things like this, politics and religion we’ve always been respectful but I’m worried she won’t understand where we are coming from on this.

I’m not looking to debate the effectiveness of vaccines with anyone I’m just wanting to know what would you say to a friend that’s already struggling and feeling alone?