"I wish I knew why Melissa and Jessica turned into boys," Athena said, holding the stone. After the stone glowed, she got her answer. And because her wish wasn't gendered, it was granted the way it normally would (when using the regular wishing stone). "Zoe, this isn't your stone. It's a different one."
"What?"
"I don't know what happened to the stone you showed me yesterday, but this one is completely different. Whenever someone makes a wish that's gendered, the stone changes the gender specified, then grants the wish. That's why Melissa and Jessica turned into boys."
Zoe grabbed the stone from Athena, looking at it. "If this is a different stone, then ... where's mine?"