"Hold it," said Jonnie.
She thought. How could she fix this? Let's see... Most of the early wishes on Sarah had been reinterpreted to apply to either her old body, which was a small doll right now, or her old self, which had been erased from reality. Still, there was that bit about Sarah's new body starting as a fetus in Jonnie's womb....
"Karyn, what do I do?" she said. "I don't know if I can change back!"
"But didn't we figure that out? It was a side effect of being merged with Sarah, you never wished for it, you can change back. The Chinese part only had to stay true until the pregnancy was over, you can reverse that too."
"You wished that she'd be a fetus in my womb. I have to have a womb for that wish to be true!"
"Oh... crap." said Karyn.
"I'm going to fix this, though..."
Meanwhile the now part Chinese Sarah was listening, very puzzled... until Jonnie said "At least I'm going to become 16 again. Too bad I can't think of a way to do it without sci-fi... I wish that I'm 16 years old... Wait, Karyn, I need that stone back."
"Mom!" yelled Sarah. "You're making no sense at all! All I can tell is that you think you're pregnant or something."
"I'll do it, Jonnie," said Karyn. She pointed to an empty chair on the side of the room and said "I wish that Sarah's asleep in that chair over there. There we go. Now we can do this in peace. Here's your stone, Jon." She handed the now older Jonnie the stone.
"Thanks, Karyn. It was getting annoying listening to her. I wish that I'm 16 years old, and that Sarah is 16 too because, uh...."