Need opinions

My cousin invited me and a few other cousins on a trip to ATL. I said yes and had set up a sitter for my son. Out of the 4 of us I’m the only with a child.

The next week I found out she told one of the other girls “I wasn’t going to invite her at first cause she has a kid and that’s no fun.”

After finding this out I told her I wasn’t going anymore. Am I overreacting? I tend to be a bit sensitive.