You can invite as many people as you want provided that they are invited to the wedding and the guest list size has been determined by the hostess.  The hostess may ask for the bride’s input on what guests she would like to invite.  Some hostesses want (and can afford) a large bridal shower, but most are limited by cost or space.  A small shower might have a guest list of less than a dozen, and a larger shower would still rarely exceed 40.  Again, people attending the bridal shower absolutely must be invited to the wedding.  The only exception is a bridal shower thrown by co-workers.