So what do you do about this problem? Well, you need to try to figure out exactly what the reward is. Typically it's looking for approval, affirmation, sometimes status. As weird as it sounds, 13-year-old girls sometimes compete to see who can have the most sex. If it is, as it usually is, affirmation and status, find other ways of going for affirmation and status. Sports are terrific. Find some sport that she's willing to do where they're playing with other girls. Build this sisterhood. Female athletes tend to have few of these behaviors, because they feel good about themselves. Pushing themselves. Achieving things on a field of competition. They tend to support each other. Anecdotally, we hear stories where team members will come up (it happened to my daughter), and say you don't want to talk to that boy, and will take her away from a crowd that was not good for her. So push other areas where she can feel good about herself. Get that payoff, so doing these other hurtful crazy things don't look as attractive.