I know it takes time, and the risk of you getting caught up in your own social media web, but mom's please pay attention to your daughter's social media accounts. Read between the lines, see just past the selfies, read the comments, look at the likes. Why? Because they matter. This is how our our youth are relating to themselves and to their society. This is how they cry for help. This is where they fall into the trap of craving approval from others rather then just being themselves. This is where they live a "lie" - a life they want to portray to others but not exactly the life they are living. This is where they lash out at you (parents) or their friends. This is where "good" isn't always nice.
Talk to her. You don't have to comment, or interact on the social media sites. More than likely that will drive her away from you. Don't accuse or attack her but ask and actually listen. Be patient, keep trying.
How our girls handle their social media sites can help or hurt them the rest of their lives. Make sure you are involved and aware of what social media sites they have and what they are posting. Training during the younger years will help them handle social media when they are older.