I'll admit that a history of broken phones makes it seem like a 350$ one seems extremely unreasonable. However, later on she explained that she helped cover the costs through her own work, her parents didn't just buy the thing for her. If it's her own loss, then I think it's a lesson well learned.

And don't we all have our bad days where we just get frustrated to the point where we let loose some words we'd otherwise tend to avoid in our vocabulary?

No, it isn't a responsible adult to have a history of broken phones-but if you'll notice, she isn't an adult, and that alone ought give her some leeway. It sounds as if she's working more than many people her age-honestly, teenagers, much as I am shamed to admit it, do crap, whine about working in fast food as 'hard work'. At least she's actually doing things that need to be done.

Helping kids doesn't entail calling them crackwhores, to be strictly honest. That's far more likely to raise their ire and have them go out of their way to annoy, irritate, or vex you in anyway possible.