There is a myriad of ways that parents can tell that their very young children are tired. They rub their eyes. They yawn. They throw fits and whine about incidental things. They refuse to go to sleep.
Preteens are a bit more difficult to read. Part of this is because when a preteen is tired, she typically doesn’t have the same resistance to taking a nap as a preschooler. If your preteen is tired, you will probably find her passed out.
If forced to function while tired, however, she may make strange cognitive mistakes that she will not remember the next day.
When we arrived at our hotel late Friday night, both the preschooler and the preteen were asleep in the back seat. The preschooler had the good fortune to be carried to the room. Jane was given a shake and told to grab her stuff and come in.
She was thirsty and asked for a drink. Her dad unwrapped one of the paper cups provided by the hotel and handed it to her. After awhile, I noticed that she was spending a lot of time at the sink. She would turn the water on for a brief spurt, then lean down close to the bowl, take a sip, then repeat.
When I got closer, I saw why. She had the cup upside down.
She protested when I took the cup from her and poured out the water. I then turned it right-side up and refilled it. She gave me a confused “Oh. Thank you.” The next morning, she had no recollection of the incident. That is how you know when she is tired.