Then 'Sarah' knew a wish she could make.
"I wish you're comfortable being in that body as a body, but without necessarily wanting to be like Athena as a person."
The stone flashed; Sarah (in Athena's body) looked a little confused. "All right, you can keep my old body. But I swear, I'm going to buy some nicer clothes. I might not mind being in this body, but I still don't like being a Goth! And I don't plan on hanging around with Zoe. There's no reason I can't be a cheerleader in this body, either."
"Now I wish that I'm called Sarah and you're called Athena. I also wish you can act like Athena is supposed to act, but aren't forced to."
"What did you do?" said the (new) Athena.
"Just sit down and lemme explain," said Sarah. "I have the same mind as you did. I have the same body as you did. I am Sarah, regardless of who I used to be. But there's room for both of us. I don't want to fiddle with your mind; I like having another person like me around. This way you can pretend to be Athena, you can mess up her life, or change it like you would if you had her life... like we would if we had her life. And nobody's going to complain. To everyone else, it's as if Athena suddenly got a clue and decided to stop wearing black... if that's what you decide. They don't know that her mind is now ours."
"Hmm," said Athena. "That's not a bad idea, except for one thing. You should..."
"... wish you some advantages," said Sarah. "I know, it's what I'd do! I wish that Athena was rich enough that she'd have no problem getting new clothes or other fancy things."
There was no obvious change except that Athena's pocketbook changed into a more expensive model.
"You know," said Sarah, "I think I have an idea."
"Woo, you're scaring me," said Athena.
"Well..."