https://www.quora.com/My-16-year-old-daughter-is-always-crying-for-unknown-reason-I-asked-her-what-s-wrong-and-she-says-nothing-shut-up-What-could-she-be-going-through-and-why-is-she-saying-this
It could be anything: she could be depressed and anxious bcs she could be bullied, heartbroken or just hate herself and the world.