Baby Shower Invitations Girls

Baby Shower invitation?
My friend came by yesterday and gave me a Baby Shower invitation for her little sister whom I’ve only met once and said that her sister said for me to be sure and bring my mom and sister’s. They have never met her so it’s an obvious attempt just for gifts. I don’t know any of this girls family besides her sister. So how do I go about this? Would it be rude not to go?
Sorry I didn’t mean to post this question twice.
I haven’t got a clue, but if the show must go on, take your own
BABY SHOWER SOAP: cool girl