Should I have sent money?

I know I shouldnt be stressing my self out about this but I need advice. My toddler daughter has a sister and their dad had a party sleepover for her hosted by his girlfriend. So the girlfriend asked if my two little sisters could come to the party sleepover and build a bear work shop , so I said sure. She said I needed to buy them a particular pajama and shirt to match the theme. She didn't ask of anything else. She kept asking if they were going to build a bear and I said they could go. But she never told me if I had to send money for it. So I purchased the pajamas and shirts for my sisters and I brought my daughter's sister a card with money in it. Should I have sent money for Build a Bear workshop?