The OP agreed to take wedding photos for her cousin’s wedding. He says, “She wanted me to take photos getting ready, our grandmother putting a family heirloom necklace on her, the first look, the wedding, the reception, etc.”
After the wedding, the OP edited and copied the photos onto individual USB drives. “I texted Sarah [the bride] a couple of days later to let her know they were ready and that I would happily meet up to exchange them for the $50.
The cousin tells OP,“By the way, Sarah was wondering when you would give her the photos. She said she would pay you the $10 if that’s the only reason you’re talking so long.”