Without asking first, Sarah turned on the radio, then tuned it to heavy metal music. She then found herself bobbing her head to the loud obnoxious song being played.
Biff was immediately annoyed. "You like this stuff?"
"Yeah, I do, actually," Sarah admitted. Funny, she never really did before, but there was just something so fucking cool about it. In fact, she was thinking she could listen to just this from now on, instead of that pop music garbage she was used to. Why did she even like that trash before, when there was music like this?
"Well, I don't," Biff said, turning the radio off.
"Hey!" Sarah yelled, shocked that her friend would do that. Yeah, some friend he was.
"My car, my rules," he said.
Sarah crossed her arms and groaned. "Fine." Then she opened her bag and took something out. If she couldn't listen to music, then she'd pass the time reading.
Biff glanced over, his eyebrow raised. "Aren't you a little old for that?"
"Now you're criticizing my comics?" Sarah asked, getting annoyed by all of her friend's objections. "Not only is Batman super cool, these comics have a dark gritty edge to them. Just my thing." At least, she thought it was. Why did it feel like this was the first time she was ever interested in comic books? After all, she had a Batman comic in her bag. Why else would it be there?
"Whatever," Biff said, turning off the road and into the high school parking lot. "We're here."
It seemed that since the Gibson family had three kids (Jon, Zoe, and Mikey) and the McMillan family only had one (Sarah), the wish made it so that Sarah was getting a combination of the personalities of Jon, Zoe, and Mikey.
Now, if there was some kind of age or gender change beyond all of this, that's totally up to the stone (after all, as was stated in a previous episode, each changed family member would stay physically mostly themselves, so while an age change might be subtle enough, a gender change might be too much, you know?)
