DD9 (my high sleep needs kid) goes to bed at 8:15 or 8:30 and is up at 6:35 for school. This is barely enough sleep for her and we have to wake her. She will sleep in till 7:30 or 8 on weekends if her brother does not wake her.

DS5 (lower sleep needs) goes to bed at 7:30 or 7:45 and is also up at 6:35. He wakes on his own and never sleeps in on weekends. He has been having trouble falling asleep for a while. We let him read in bed before lights out and I think it's actually too stimulating, but now that we've started this I think he would kill us if we took it away. I think he also needs more sleep, but am not as sure.

DD would benefit from going to bed at 8, but with a 4-year age gap she needs to feel like she gets to go to bed later than her brother.