Wedding announcements: Is this a gift grab?

My cousin is getting married and she sent out wedding announcements. My family got one and we opened it up to find an announcement card and a gift registry card. We aren't even invited to the wedding, according to my cousin's mom who says that the wedding is supposed to be for my cousin's friends in Texas and her immediate family. We are offended and are now trying to decide whether or not to send a gift because we're family anyways. Is this a common wedding practice or a gift grab? Should we bother sending gifts?