Karyn went into the other room and held the stone in her hand as she said, "I wish that Jon and I would swap lower halves."
There was a flash of light and Karyn looked down at herself. Yep, that was definitely Jon's body below her waist. She even recognized the pants that she had just seen Jon wearing. She thought about doing a little exploring on her new lower half first, but decided to check in on Jon first.
She walked back into the other room and was shocked at the sight of Jon. She expected to see Jon looking the same as before, except with her lower half. But Jon was now dressed like a typical teenage girl. His hair was longer and styled, he was even wearing make-up. What did the stone do?
"All right, Karyn," said Jon. "What'd you do?"
Then it hit Karyn, in this reality, Jon had always had her lower half, so he had obviously been raised as a girl, and nobody probably even noticed anything wrong till he hit puberty and his upper half developed like a male's.
"C'mon, Karyn, tell me what you did so we can get back to trying to solve your problem."
"Problem?" asked Karyn. "What problem?"
Jon rolled his eyes girlishly. "Aw, gee, I don't know, maybe the fact that you accidentally wished for boobs and long blonde hair. It must be embarrassing for a guy like you to walk around like that... Unless wait..." Jon suddenly put his hands to his face, shocked. "You didn't do that on purpose did you? Do you really want to be a girl?!"
Karyn wasn't sure what to do next.