Wedding Shower Ettiquette

I attended a lovely shower last evening. During the discussion it came out that I was one the only one in the room who had received an invitation to the wedding including the hostesses of the expensive restaurant event.
Apparently the bride had asked one of the hostesses to give the party for her and the bride supplied the guest list. Everyone there thought and may still think that they are invited to the wedding.
Should I say something to the bride? Should she return the shower gifts?