I hope that she never loses it, because it is the coolest thing to see. When Quinn is tired, her eyes will occasionally quiver, especially as she is fighting sleep. It is not something that she can do consciously, but literally back and forth about 6x per second, usually lasting only a second or so.
I'm remarking on it tonight, because usually it is expected (to us) and don't remember to blog about it... but tonight / today Quinn isn't feeling well. She had a temperature since mid day and ended up taking 2 naps. (She normally doesn't take any). The last nap ended at 6. So by 9 (the time she is normally asleep (bedtime starts around 8:30), my expectation was that should wouldn't be tired. And she was meeting my expectation, was awake, not wired, as I still think that she felt off, even after the medicine, but singing and reading and otherwise fully engaged.
And that is when I noticed the quiver. I started singing some bedtime songs, which she sung along with me. Then the next thing I new she was sleeping. It kind of reminded me of the scene from "A Princess Bride" where he says laughing, "Never mess with a Sicilian when death is on the line", then keels over. (BTW I don't look at her while singing as it makes the bedtime songs less engaging, so when I did look back she was asleep - but moments before, she was singing with me).