Coworkers throwing baby shower!

So my coworkers decided to throw me a baby shower, which i am super appreciative of. Though my only concern is that they’ve started inviting coworkers I don’t like..or hardly know outside of work. I’m an introvert by nature and i find it hard to tell the people that are throwing this shower no. I have a hard time saying no in general..my mom and best friend are also coming to this because like i said, I’m an introvert and keep a pretty small circle. So my question is, do I tell them I don’t want certain people there? I don’t want to be rude or unappreciative of their efforts..and don’t really want to say no to them. But them inviting certain people has made me a bit uncomfortable. This Baby shower is outside of work on a Saturday in May. What should I do?