Do I still have to buy a present?

I have been invited to a friends confirmation for her daughter, she has now cancelled the communion party. She stated after the mass they are going to a cafe where people can purchase their own drinks and food out of their own pocket. Do I still have to buy a present if i am only going to the mass. I always throw a party for my kids at my own expense, but to me sounds like she is inviting people to the mass for the presents with no celebration afterwards.