I am guilty of giving in to my obedient, cooperative 12-year-old who does her chores cheerfully. "Everyone has musical.ly, Mum!' I added it and set up my own account and befriended her so I could monitor her. We checked the 'privacy' settings and googled the feedback and set rules about being in school uniform etc. The 13+ age restriction is standard on social media platforms and we talked about how it was a privilege to use it 8 months before she turns 13.
How naive I was!