Karyn watched Jonnie leave, wondering about her mistake. Jon had changed back from a Chinese girl when she fixed the wish about a "little Chinese" to mean the food she wanted. The only reason Jon was still female was that when he wished Sarah away, he had turned into a girl who had Sarah's father and lived in Sarah's room; basically he and Sarah had been merged.
Well, after Karyn's slip-of-the-tongue wish, Jon was now Chinese again. It shouldn't hurt him any more than being a white girl, so it was really nothing to worry about... though it did mean that she had just changed Sarah's race, since Sarah would have to be born at least half Chinese.
At lunch the next day, Jonnie and Karyn were sitting together.
"I'd like my stone back," said Jonnie.
"What?" replied Karyn.
"The stone... you know the one you used to wish Sarah into me... It is mine, you know."
Karyn realized that Jon may think he's this Chinese girl and only remember this girl's life, but there's no reason the stone couldn't be a part of her life. After all, before the Chinese wish, she still had one parent the same; for all Karyn knew she still did. She could certainly have the same grandfather, who gave her the same inheritance.
Karyn stammered and finally said "I'll give it back if you don't wish the baby into me."
"I wasn't thinking of that," replied Jonnie.
"Well, what were you going to do?"
"Here's mi idea...."