We're looking at this all wrong.

First off, if you think of Galleria as some spoiled rich girl who has always gotten why she wants because she's an only child, her behavior is justified. Chanel reminds me so much of the urban Hispanic girls I go to school with, where she boasts about her heritage, but tries to be everything but. Aqua constantly has something to prove being from the country and coming to the big city, which has definitely made her a little tough and difficult. Dorinda is the girl who, though they didn't realize it, the girls pitied.
Since there's no reason to watch it with the same innocence we did when we were kids and didn't really know much about foster kids, credit cards and contracts, if you watch it like this, it's not unrealistic. However, that does not make it a good movie.