"I don't know what's going on here," said Mom "But I'll get to the bottom of it. Both of you, inside. Now."
Still carrying the medallion, her two bigger sisters followed mom into the house. Brin watched as one of the two put the medallion down on the couch and put a white towel around her shoulders, while the other put a red towel around her shoulders. This would be tricky. The medallion was out in the open, so it wouldn't be easy to take, but from what she'd seen, all she had to do was touch a piece of clothing to it to change.
A plan forming in her mind, she went up to her room and gathered together her dirty clothes, and took some from her sister's room, as-well. As plans go, it was pretty simple: drop a piece of her sister's clothing onto the medallion, then pick it up to trigger the transformation. She walked downstairs, confident that her plan would work. She was barely listening to the conversation, as the twins kept answering mom's questions in unison. It was pretty annoying. Still, she didn't think she would end up like that, from what she'd observed. Stage 1 of the plan worked, her sister's blouse fell off the top of the pile onto the couch, obscuring the medallion from view.