"Er, we change back?" said Jennifer. "I wish that we knew what it's like to be helpless girls, because we know what it's like to be like this, but we can remember it so we don't have to stay like this."
"Good idea," said Josephine. "Now I wish I'm at home. I mean we're at home..."
Josephine suddenly saw things change around her. She was now in a room that looked a bit like Jon's room if only because of how the furniture was arranged, but there were some dolls, too many cute decorations, and two beds in the room. But it wasn't going to last. She could just change back.
"I wish that Jennifer was here." Nothing happened.
"I wish I was Jon again." Nothing happened.
"I wish I knew why that didn't work!" Nothing happened.
But then it occurred to her. As Jon, she had swallowed the stone, and its magic spread through his body.
Then the accidental wish made Jon into two people, Jennifer and Josephine.
So the magic was now split up between Jennifer and Josephine. They probably had to both be in the same place in order to make any wishes--otherwise there wasn't a whole stone around! Jennifer and Josephine were stuck as 10 year olds, unable to make any wishes, until Jennifer got back to the house and they were in the same place again. At least nobody could make accidental wishes either.
