With a quick flash Jon realized that as far as everyone was concerned, he was now and had always been Sally as he had her life now per his last wish. He was now the very girlie girl that opted for a skirt or dress over pants.
The original Sally was now and had always been Jon, but now only knew herself to ever be Jon. In the confusion of the wish being granted the following had happened.
Jon became Sally and had her life. Sally became Jon, who had wished to have Sally's life so now had all of Sally's memories making the body of Jon think it was once Sally and now no longer knew of the stone, which is why it was left in the bathroom.
Jon had to figure out what to do to fix this, but with a poorly worded wish that started this mess, what was he to do. Before he could decide a knock on the door interrupted him and it was ...