From our panel of staff contributors
Sleep cycles are as individual and unique as every human being. Enforce a few rules — a time to go to her room, no games, Internet, TV, loud music — then let her figure out when she needs to go to sleep to function the next day. Even without your rules or permission, she will.
Making sure your children eat and sleep right is still your job, even though the scale of responsibility tips more in their direction as they get older. Your sense of their internal clock could be a guide. Notice how it affects them in the morning. Are they dragging, or are they rested? Teens are testing the limits of their bodies, and staying up is a way of testing their adulthood. Try to accommodate them by agreeing to a reasonable time, based on how much sleep you think they need every night, and make sure they understand that the later hours are "quiet time." Other than that, my main concern would be what they're doing with that time. I would put conditions on what they do with the extra time. I'd make a rule of little or no screen time, and point them toward productive — and tiring — activities.
She is realistically too old for a strictly imposed bedtime, but not too old for some firmly enforced nighttime parameters.
"You can't say, 'You must be asleep by 10:15,'" says clinical psychologist Roni Cohen-Sandler, author of "Stressed-Out Girls: Helping Them Thrive in the Age of Pressure" (Penguin Books). "You can say, 'Look, just as everything else in this house, we have guidelines for good health, and I'm not going to allow you to stay up all night.'"
Research on sleep and teens shows they need about 10 to 12 hours per night, says Cohen-Sandler. And they're often getting six or seven.
"The effects on their mental and physical health are profound," she says. "During sleep is when the brain repairs itself and a lot of memory consolidation occurs. Not to mention the immune system becomes shot when they deprive themselves of sleep.
"Just as parents have an obligation to protect kids' health in terms of good eating habits, we have an obligation to help them establish good sleeping habits," she says. "At 15, a child is generally not in a position to make good judgments."
She suggests educating her about the importance of sleep and putting boundaries in place to help her achieve more of it.
Remind her to keep an eye on caffeine intake. "Girls often are drinking many, many caffeinated beverages throughout the day and into the evening."
Take away tech. "Say, 'At 9:30 or 10, that's downtime. No more computer. No more video. No more phone.' Take the screens away. Technology is highly addictive and the light is activating chemicals that increase wakefulness."
Encourage reading or listening to relaxing music. "Often they get in bed and can't turn off their brains. 'Did I do everything? Did I do everything well enough?'"
Help her schedule the waking hours. "Often they're so busy and stressed that they're staying up late to do things they haven't had time to do during the day. Or they're staying up to do even more work."
Don't assume, at 15, that your child knows what's best for her brain and body.
"The frontal lobes of a teenage brain are simply not fully developed," says Cohen-Sandler. "A 15-year-old is not capable of laying in bed and thinking, 'I really want to check Facebook, but I have two tests tomorrow and sleep is more important.' They're just not able to delay gratification and think about long-term consequences like that."
Thankfully, you are.
Have a solution? Your 8-year-old's room is a constant disaster. Is this a battle worth picking? Find "The Parent 'Hood" page on Facebook, where you can post your parenting questions and offer tips and solutions for others to try.