The ages would absolutely be helpful here. Plenty of babies are born to women in their 40's. It's not as uncommon as people think.

Also, heebie jeebies, really? OP doesn't give their reasons for being child-free but being responsible for a whole human is nerve wracking and can be anxiety/panic inducing for some people. That is not simply being afraid or having "heebie jeebies".

OP is facing the consequences of how she's been treating people though. There are ways to get out of playing with children if you really don't want to play with children. But the family emergency thing was a bit on the harsh side. I get no is a complete statement, but if OP didn't want to watch the kids they could have offered to help find a babysitter or to stay with the adult brother at the hospital. There are ways to support your family in an emergency without being the babysitter yourself.