Who do you invite to a baby shower??

I'm visiting my family and they want to throw me an early baby shower before I fly home. I don't really know anyone who's in town here though that I could invite! Maybe a couple close friends and then just my immediate family. I'm feeling pretty lame not having anyone to invite and feel like I'm letting my mom down since she wanted to throw this but I just don't know what to do. I feel like you're supposed to have lots of girl friends and women family to invite and I just don't :(