Jon Never Existed

Karyn was quick, but Sarah was quicker. She snatched the rock from the floor and said "My god, Jon. What do I have to do to get you out of the way? Should I wish that you never existed?" The stone flashed and Jon disappeared. And since Jon never existed, his grandfather never gave him the wishing rock. Instead, he gave the rock to Jon's sister, Zoe. Sarah looked around, confused. She was doing something, but what was it? And why is that Karyn girl here? Karyn didn't remember Jon, because to her (and everyone else) he never existed. So **she** wondered why she was there too. And Karyn would never know about the stone now. Oh, she knew Zoe before the wish, but the only reason she knew Zoe was because she knew Jon. But now Jon doesn't exist anymore. So, what will happen to the stone?