@ossobuco,
Some people of all incomes and ethnic groups have anger or anxiety in life problems, and possible mental health problems that are not getting addressed. Some people of most cultures may hopped up in some way. Also, cultures differ. Even lining up may be odd to some cultures, to us who line up.
In my urban design type studies, in some beginning class, we were assigned books* on the matter of people and their sense of personal space. We were also assigned the task of nudging toward people in a grocery line, or similar line, to see where discomfort happened, for other people, and to report on it. There are books on all this.
I say this not knowing what your niece did, one way or another.
*I might remember those books, I've two in mind but don't remember the titles, will be back when I nab the book names. One was by Christopher Alexander, something about patterns, another by William White (I just remembered). Both worth a read, even though much has probably been written since their books.
What is the deal with your naming people as ghetto, miss princess?