Twin Stones: Karyn fixes it?

"The stone!" thought Karyn. "How did I get the stone?" She held the stone tightly, and decided she had to reverse the wish. She didn't want to be twelve years old! Then Karyn remembered the experiments Jon had done with the branch... she'd have to reinterpret the wish carefully. "I wish that I fit in these pants because the pants are for a 16 year old girl, and I fit into those." Soon, Karyn was back to normal. But Jon, who had the other stone and didn't know they were twin stones, felt himself transform. Shocked, he realized he was twelve years old! Then, he transformed a second time....