Tonight with your 13 to 17 year old
The prompt
“Have you set any kind of limit for yourself around your phone or sleep that you're actually sticking to?”
What to listen for
If they describe a self-imposed rule, even a small one like "no phone after midnight", that's them showing you they can govern themselves, which deserves real credit, not a follow-up rule from you.
If they admit they've tried and it hasn't stuck, that's honest self-awareness, not failure; the fact that they're willing to admit it to you is the win.
If they get defensive or assume this is a lead-in to a lecture, keep your reaction light, the goal is to learn what they're already doing right, not to check up on them.
What this tells you
This shows you how much they want to be trusted to manage themselves before anyone else steps in.