My daughter has tons of brain damage. On a scale of 0-10, 0 meaning no brain damage, and 10 meaning dead, my daughter is a 5.
You would not tell by looking at her that anything is wrong with her. She still has a speech problem, but she is only 10. I am sure that when she is an adult most people will not know she has a problem.
She is extremely good (to 95%) in math for her age.
She does have some auditory memory problems, and her reading is a little below grade level.
However, she is not in a wheelchair. She can run, jump, ride a bike, swim, eat, and think like a regular 9 year old.
The brain is amazing, and we don't know that much about it.
I'm glad your daughter is doing well and I hope she continues to do well! The scale given doesn't mean anything to me though, because it's arbitrary and completely undefined. Yes, the brain is amazing. I would say that some people know very much about it, how it works and how it's component nerve centers provide function.