Bridal Shower Etiquette 2 Situations

The bride`s mother is deceased and I am a step mother. I am helping her with most everything. She wants me at her bridal shower that a friend is giving her. Do I bring a gift? What are my responsibilities?
#2 I am giving her a tea party for the other people that are helping her and future relatives at a formal tea room and do not know where to start and what to do. I am needing help and suggestions.