Pacing back and forth in her bedroom, Karyn thought about what to do. Jon no longer existed, but the stone still might. Erasing Jon's mother probably didn't erase Jon's grandfather, who was the previous owner of the stone. Jon said that his grandfather died from natural causes, so no matter which reality it was, he was probably still dead. And that meant that the stone was probably given away to a family member. Jon and his family no longer existed, but Jon had an aunt and cousin living in the next town. Perhaps one of them inherited the stone.
Of course, all of this reasoning hinged on the assumption that Jon's grandfather still found the stone on one of his archeological digs and decided to give it to a family member instead of one of his colleagues. But it was the only path for Karyn to take.
"Karyn," she heard her mom say. "Shouldn't you be getting to school?"
She wasn't sure if she even wanted to go to school, for once. Not with this situation happening. But she had never skipped school in her life. Even now, she wasn't sure she could do it. And Jon wasn't going anywhere. It didn't really matter if she wished him and his family back that morning or next week.