Bridal shower

My maid of honor just texted me and asked if "her brother's baby mama and baby" (her exact words) can come to my bridal shower. We had to cut down the list quite a bit because we wanted to keep it under 100 people to begin with. I'm not throwing my own bridal shower, meaning I'm not the one paying for food and everything,  and they were not invited because I don't know them. I don't want to be rude but how should I respond?