Someone asking to be invited to your party...

I'm having a gender reveal party on May 7th and I invited only close family of my husband and I. Well anyway, a girl (that I only met once) that is friends with my husbands cousin asked me on Facebook if she could come to my party. Does anyone find it kind of rude to ask for an invite? Or should I be flattered that she is excited about the baby? Also, should I say yes or no? I want to say no but I feel bad and don't want to be mean...HELP! Lol