Seeking advice on dealing with 16/f being in a clique

My daughter has apparently been involved in a couple of cliques; in school, and now on staff at a camp. She's an extremely attractive and outgoing girl, but seems to have fallen into a group that is exclusive and emulates the kind of behavior that I'm not proud of. Looking down on others that aren't in her group, harassing those that aren't "in", belittling others' jobs, arrogance, etc. This only came to my attention recently through a conversation with her older brother who is also on staff. He didn't tell me as a "tattle", but because it concerned him and he wanted my insight on the topic. It aligns with the behavior she displays at home during her off periods on the weekends. It manifests as general disdain for the rest of her family. We've always been very close, so it's easy for me to notice the change. Eye rolling, shortness, impatience just to name a few. Having a conversion with her about her brother's behavior towards her, she left out a couple of key points that her brother filled in. You don't know these kids, but I'm leaning to my son's account being more accurate, especially in light of her changes in behavior. She's "the cool kid", and very much so needs that sense of being accepted. (Bio dad is a user, and has created some deep issues. He hasn't really been involved for many, many years with the exception of trying to exploit her online to make himself look good to new girlfriends)The background is to ask for some input on how to approach her, about her involvement in cliques. The desired result is for her to shed the need for the feedback that exclusive groups gives. Any thoughts? via /r/Parenting http://ift.tt/28WgzG5