Brooklynn Prince is the star of the movie. Watching her reminds me of running around as a little kid, going on adventures as a free range child of the 70s and 80s... The ending is another story, but dont let that upset you, a lot of people were upset in my showing.
I agree with you except on one point. In the case of the mother, I don't feel at all she's unfairly suffering. She's selfish, is not sacrificial about what's best for her kid and needs to do more than lay around the hotel and smoke. If she was a disabled vet or a laid off from a job through no fault of her own that would be different. Let's not glorify people's laziness or bad choices.
She was trying in her own way, with selling the perfume, trying to get that waitress job through her friend and eventually resorting to prostitution to make money for her and her kid. Remember, she also had a criminal record so getting hired at most jobs probably wasn't easy for her. But yes, she was obviously a troubled person with little guidance or direction.