A student who is well-read can pick up vocabulary and phraseology from places other than home, though I suspect she wouldn't be reading the type of material that would lead her thinking this way without encouragement at home.
There are some slight errors in usage of words that I find very consistent with the writings of a child that age, who is wise beyond her years in some ways but still not a fully mature writer.
However, the main thing is that whatever her age and whatever her background, the young lady makes some outstanding points. I only wish that many more adults shared her views!