But she woke once in the night to hear soft sounds as if Jandria was crying.
I woke once at about two that morning, and wondered what had disturbed me.
He woke once in the night, and leaped from the hammock with a start.
He woke once in the night, a few hours before Kimberly would.
If you use this approach, waking once a night should be enough, perhaps right before you go to bed yourself.
Gold once woke me in the middle of the night and I broke his neck.
Waking once or twice at night as you get older is very common and doesn't indicate a problem.
He woke once, just after dawn, when the otters stirred out of sleep and left them.
He woke once, peering into the darkness, as some night creature crept by.
I woke once and saw one just sitting there observing me like a dog.