Follow the steps in the article. Talk to her in a calm place, and don't get angry or mad or upset. Tell her you love her and you don't want her upset, make it feel like you are on her side.
The first step is figuring out where she gets the phone. Does she get an allowance and use that money? Stop her allowance. Her friends? Limit interaction with those friends....
Do something that shows your daughter you love her. Maybe take her roller skating or another activity she used to enjoy when she was acting like her old self.
I'd recommend you get to know her better. But before that, get to know yourself. You have to understand what she meant by "emotional" and "moody. For example, it might...