Katie wasn't a big fan of the new Kelly. Her mom's attitude had changed now that she herself was sixteen, and not for the better. She rolled her eyes and treated Katie like an annoying little sister now. She was more interested in boys and looking hot and sexy than anything else.
Maybe if I have the knowledge she has, Katie thought, I would understand why better. So she decided to make a wish.
"I wish I had all the knowledge and skills of a sixteen year old girl, including how to drive, along with my current memories."
Katie felt the effect on herself immediately as the knowledge of a sixteen year old filled her mind. It was a lot to take in, conflicting with her former innocent seven year old personality. It felt like she'd simply woken up and had a gap of all those years with memories, but she still had the knowledge and experience she should have anyways.