I'm a nanny for an almost-12-month-old. She's never napped just really well, but usually sleeps for about an hour, maybe 75 minutes, twice a day. I helped to sleep train her a couple months ago (CIO), so she's putting herself to sleep now. Last week, she started waking after 40 minutes, crying, and will NOT go back to sleep. I let her cry (with checks) for an hour one afternoon last week, and she never went back down.

What would you do? Her mom is thinking maybe it's time to start making the switch to one nap. But she's going to sleep really easily, so I'm not sure how to keep her awake any longer. And I'm scared that she will still only sleep for 40 minutes, once a day, and that is NOT enough sleep for her.