Because these were the Twin Stones, the wish was granted to both Jon and Sarah. But if Sarah had wished that same wish, then the word "she" would probably have been in reference to someone she was looking at when the wish was made.
And right now, the "she" that Sarah was looking at was none other than that stuck-up Bible-thumper girl Nadine Ferguson. She was just passing Sarah in the hallway. Totally a chance encounter.
The moment that Sarah's stone glowed, Nadine's entire reality changed. Obviously, the Ferguson family frowned on the gay lifestyle, so when (in this new reality) Nadine discovered that she was attracted to both boys and girls, she hid it from her parents and her friends and everyone else. She tried to deny that she was bisexual, because that wasn't right. Being gay was a sin. Her parents told her that and so did her church. But the older she got, the stronger her feelings towards other girls got. And now as a junior in high school (it was spring, so her senior year wasn't too far away), she couldn't even look at a female form without becoming aroused.
When she passed Sarah McMillan, reportedly the hottest girl in school, she just couldn't take it anymore. She grabbed Sarah's arm and pulled her into the nearest girls restroom.
"What the hell are you doing?" Sarah asked.
Nadine answered by kissing her, shoving her tongue deep into her mouth. But Sarah didn't stop her. She was bisexual too and was loving this unexpected turn-of-events.
