Sleep needs vary wildly: some people need four hours, others need ten or more. Teenagers need 10-12 hours, and girls may need extra sleep during their periods. The key is flexibility, not rigid schedules.
Chapters
You said things that they're a night owl. If I can give the audience any information right now, it's to figure out what your own sleep requirements are and when. So how long and how much? Some people don't have no idea how much sleep they need or want. And I say sleep because it's relative, right? Some people need 6, some people need 4. My dad only needed 4 hours of sleep and he functioned just fine. Some people need 10 hours. Growing teenagers absolutely need 10 to 12 hours. Parents, let them sleep. These teenagers, especially the boys, they need to sleep. Girls during their periods, they need to sleep. Let them do that. All right, and it doesn't necessarily have to be on your schedule, but at least allow them the opportunity to just rest.