My daughter is 14. She has inattention and not so much impulse control issues. She went through a real difficult stretch about age 12 – 14. Between the hormonal changes and social changes they encounter during these years, their mood and attitude can be very erratic. Then add in the challenges with emotion and impulse control for our adhd kids, and you’ve got a great deal of friction start up. I would be sure that there is nothing important that is upsetting her that she is not sharing with you. Then, just continue to talk with her about her disposition. She seems very motivated by her phone privileges so I would stick with that. It is also important to set the expectation that you occasionally will look at her phone to check on the social media piece. I was very surprised to see what the kids were starting to be exposed to! It will give you an opportunity to provide much needed guidance!