@John Demille
When she walked away I noted that she had much wider hips than a pre-teen, so that part of her development worked properly. She was a well formed tiny woman.
That's why I asked if it was a case of full arrested development or just stunted height.
My mother was only 4'10" before she stared losing height due to old age issues. She never looked like a preteen as an adult, she was fully developed, just short and slender when I was younger.
I have one sibling, an older brother, and when we were in our teens, it wasn't uncommon for someone who didn't know us to think our mother was our sister.
ETA: Wisconsin has more recently added a requirement for children up to 80 pounds (with an age cut-off) to use a child booster seat in cars.
If that requirement had been in place without the age-cut off, my mom would have graduated from high school before she escaped from the child seat.