Yay! Pics? I bet it’s little.Just updating for any one else with this question now that we've had an egg (and another one this morning!)
We put them all in the nesting boxes a couple more times - just plopped them in there after catching them. Our olive egger seemed the most interested (in that the others had no interest), so we did it a few extra times with her. She's also the smartest, so she seems to have gotten the picture.
She started squatting about two weeks ago, consistently about a week ago. Around that time, she also started screwing around in the coop more, digging in the shavings. And we noticed more digging in the boxes the last few days.
And then, yesterday, an egg!
All of which is to say, that - unsurprisingly - everyone here was right. They mostly want to do the right thing instinctively, and will do it when they're good and ready. I don't know if our showing them the egg boxes helped - but it certainly didn't hurt, and made me feel like we were *doing something* while we (im)patiently waited for eggs.
(Based on some searching on the boards on my next question, I also plan to just leave a fake egg in each box; that seems to be the consensus.)
Thanks again, folks!