I'm sure this questions has been asked a million times but I've looked over a few pages on a few boards and cant seem to find anything.....Please point me in the right direction if you happen to know

My sis is asking me for my Bridal Shower invite list and I'm kinda stumped as to exactly whom I should have her extend the invitation too. Obviously Mom, Sis, Maids...other than that is it just close aunts/cousins/friends?
I've been to showers where practically every woman who was invited to the wedding was invited to the Bridal Shower.
I do know that Golden rule of, If they're not invited to the wedding it's poor etiquette (and manners IMO) to invite them to any pre wedding events.
Thank you ladies!