Jane was glad that she was at least in the same room she was in, in her (former) mother's house. Of course, the earlier wish that Jon be in his room couldn't be reversed, so she had to be there.
She searched through her memories. She had one child, named Jessie. Both she and Jessie were staying with her sister.
Jessie was about the age Jon used to be, and was Karyn's best friend.
She walked down the hall and into what she now knew was Jessie's room. She opened the door and saw Jessie there, along with Karyn. This may make things a little easier, she thought. Just a little. At least she didn't have to remember Karyn's phone number.
"Uh, Mom?" said Jessie.
She glared back.
"Ahh, never mind.".
"Never mind me not knocking," said Jane, "I want to talk to Karyn. Alone."
Karyn looked between Jane and Jessie and said "No, Jon. If it's what I think it's about, we need to have Jessie here."
"Jon?! Who's Jon?" said Jessie.
"I am," said Jane. "This is all wrong...." she said. "You didn't exist a moment ago."
"Really," said Jessie.
She pulled the stone out of her pocket and said "I wish you'd believe my story! My name is Jon. I'm about as old as you. I inherited a magic stone from my grandfather which grants any wish, but wishes can't be reversed. My brother Mikey stole it and wished that I'd stand still. He didn't realize wishes can't be reversed. I got the stone back. I think it's because he gave it to me, since he wished that if I just took it it would return to him. [Author's note: fixing my own mistake. Considering how much this depends on overly-literal wishes, I couldn't let this slide by.]
"But I didn't just exist!" replied Jessie. "You've been my Mom for my entire life..."
"But you have to believe me anyway," said Jane. "Now, the rest of the story. I had to figure out how not to stand still." She carefully put the stone back so she wouldn't make any accidental wishes, and continued. "He said 'I wish you'd stand still.' So I wished I was a different 'you'. That way I could move without reversing the wish."
"Why didn't you just wish you were standing still because your shoes were glued, and then step out of your shoes?" asked Jessie.
"You think you're smart," said Jane. "He also wished that my parents would, quote, 'ignore you', unquote, and that they'd think they only had one son. I needed to fix that too. Gluing my shoes would only fix one wish. Not being the same 'you' would fix both of them."
"Jon, you aren't really going to reverse the wish, are you?" asked Karyn.
"I don't know..." replied Jane. "I don't even know how."
"You could at least become a teenager and have your parents again," said Karyn. "It would have to be a girl since your parents think they only have one son."
"What happens to me?" asked Jessie. "I don't want to disappear, or lose my memory..."
"People don't lose their memory if they hear the wish," said Karyn.
"If you don't lose your memory," said Jon, "and if you still exist, you'll remember me as your Mom and nobody else will, except for memories me and Karyn carry over. Are you sure you want that?"
"No, I'm not sure!" exclaimed Jessie. "How could you spring something like this on me, Mom?!"
"Don't yell at me! We're going to sit down and decide what to do here...."