Your childish anger overcomes you, the unfairness of the situation overwhelms your common sense, this mean lady changed you and you were absolutely not going to back down!
You snatch a rock off of the ground and hurl it at her head as hard as you can. As the rock hurtles toward her it changes direction and in a flash the girl is back in front of you, her expression a glare that forces you to take a step backward.
"I see..." She says as she raises her hand, "I warned you."
You feel a wave of dizziness come over you as you stumble backward. The girl continued to become larger, as does everything else. You feel something in your ballet leotard, which had seemingly shrunk with you, begin to grow larger and bulkier as it pushes your legs apart at the crotch.
You stumble and fall, your bottom striking the ground and releasing a loud crinkling sound. You try to make sense of what is going on but your mind feels slightly fuzzy.
"What... What did you do to me?" You ask.
"Just what I said I would sweetie." She said as she knelt down over you, "You didn't go back to ballet class so now..."
The teenager, now infinitely more of an adult than you are, reached you and squeezed the object around your lower body, which you realize in horror was a diaper.
"Now, you get to start over." She smiled, "Don't worry, your mommy and daddy won't realize anything about you has changed. You're their sweet baby girl now. Your little sister? Well she's far older than you now. Don't worry though... I'll let you remember your old life... But..."
A sharp pain goes through your head, "What?" You stammer as tears come unbidden to your face.
"There goes your education." She grinned, "You can't read, or write, or do any math... You can't count, you don't even know your letters anymore."
You begin to cry as she laughs and walks off, a few seconds later you hear your mother's voice, "There you are!" She says as she lifts you easily in gargantuan hands, "Did my little pumpkin wander off?" She asks in a sing-song tone.