**A trial of 9:30 PM could be reasonable, depending on when she needs to wake up.** There’s no single correct bedtime for every 12–13-year-old.

At 12, the recommended sleep range is **9–12 hours**; at 13–18, it’s **8–10 hours**. Those age cutoffs are guidelines—her sleep needs won’t suddenly drop on her birthday. [CDC sleep recommendations](https://www.cdc.gov/sleep/about/index.html)

For example, if she wakes at 6:30 AM:

- 9:00 PM allows 9½ hours in bed.
- 9:30 PM allows 9 hours.
- 10:00 PM allows 8½ hours.

Actual sleep will be shorter if she takes time to fall asleep.

I’d agree together to try 9:30 for a week or two, keeping her wake-up time consistent. Check whether she wakes reasonably easily, stays alert at school, and feels rested. If she becomes noticeably tired or struggles more in the mornings, move bedtime earlier again.

It’s also normal for puberty to shift sleepiness later. Keep a quiet wind-down routine and put screens away an hour before bed. [American Academy of Pediatrics guidance](https://www.healthychildren.org/English/tips-tools/ask-the-pediatrician/Pages/My-teen-is-having-more-trouble-falling-asleep.aspx)

Starting high school alone isn’t a reason to move bedtime later—an earlier school start might mean she needs the same bedtime. **What time does she get up on school days, and does she actually fall asleep around 9 now?**