This is just another case of folks using a word and its meaning varies all over the ball park.
What your daughter has is “irregular wear”. The trem “flat spots” or "cupped’ is sometimes used to described this - and unfortunately, those terms will lead folks to a wrong diagnosis.
Irregular wear is usually caused by misalignment and aggravated by insufficient rotation practices and insufficient inflation pressire. So the first thing to do is to get an alignment.