i am not a pshchiatrist. but, i have seen too many children with various kinds of social, academic and behavior problems. you got to know your child better. being a parent, you not only provide her materials necessary for her life, also nurture her social, mental, spirital development. in this group, there are so much bad advice. for those people, either they do not have school-aged children here in america, or they they just want to mess you up. please do not go to physical. being physical or language abuse only push your daughter to a wrong way, earlier and further. you got be your daughter's most trustful friend. she wants to share and discuss with you, of her problems in her life and school. you also need pay close atention to your other daughter. there is a phenomen called sibling rivary. many times, you, as a parent, probably do not even realize, but, to her, your attitude, lanaugae, even body language, has been interpreted as she is not your favored one. that directly cause feud between sisters, and rebelling to parents. so, never compare any of your child to her sibling or to anybody else. again, there are a lot of things involved. you shall and should discipline her if she does something fundementally wrong. how, to what a degree, in what way? complicated. got to get rid of her bad friend(s). got to find somebody she trust, respect, to be her new friend(s). teachers are so important. you got to find what she does in school, what her attitude to other kids, and vice versa, others to her, any bully, if she has difficuty understanding, etc.. especially find one teacher, one is enough, to whom your daughter respect, trust and is willing to listen to. one teacher can change your life. unfortunately, kids have different teachers every year. but, you still can find a good one.
good luck.
