Am I overreacting for how the people in my bookclub are responding to a new member?

I’m in a book club with some girls I use to work with and their regulars. We had about 12 people when we first started and 4 of them never came, read the book, or participated in anyway. About 3 clubs in we removed them due to inactivity. I have a friend (yellow) who was looking for another club since her old one was ending due to the place closing. I asked my group if she could join and got a collective “yes.” She knows 2 of the other girls in the group. She’s not just a straight up stranger. She is active in our group chat and read the book. We had our first club since adding her yesterday. One of the girls (green) always host book club - no idea why, she just insists (this is important.) so apparently everyone except me and another girl thought that yellow “was too much” and “too much energy”. Mind you we’re are a crazy loud group of girls and she was no more than any of us. I do think she was trying a little hard to fit in but this was her first time meeting most of the girls. Later I find out that green (the host) is threatening to not host anymore if yellow stays in the club. They had one interaction with her and barely even talked to her. I feel like I’m in high school with a bunch of mean girls again. Am I overreacting?