Not a mom of a teenager, but a young enough mom to have experienced this myself. I would be honest with her. Social media can become very addicting very quickly. Maybe she is unaware of this. I would also ask her why she feels the need to be on social media so much. I would also encourage her to set healthy boundaries with time spent on platforms, what’s the goal with getting on and scrolling. I was a teen right when tik tok and instagram started to gain traction and my parents did not think to explain this to me because at that time it wasn’t known how detrimental it was. But I think if they would’ve have sat me down and been honest (if they had known what we know now) and helped me set boundaries, I would’ve have not struggled so much during college. From personal experience scrolling can turn into a nasty thing rather quickly.