We don't know the childs situation at home. (At least, I think we don't. I haven't read through the majority of this thread so forgive me if I am speaking out of ignorance.) We cannot say that "discipline" is the problem here. In fact, I don't think discipline even plays much of a factor here. I think there is a lack of love in that childs household, and that could very well be the reason as to why she is acting the way she is.