Well Reg calmed down enough to focus on the task, and transfigured her head into a giant goldfish head (super attractive, right?). She would have helped anyone who needed help with transfiguration and wanted to go that route.
Once she was in the water she tried to stick with her team, but got to her sister as fast as she could. Sirilla was her first priority, but she didn't leave to go back until her entire team was free. Then she basically clung to Sirilla for the rest of the day.