I guess we missed on the 21-day hatch date, our fault not hers. Two of the chicks hatched yesterday. One looks totally blonde like mom (which doesn't mean anything) the other is mixed. It is possible that she, our only Buff Orpington hen, was bred by Big Roo, also a Buff. It is probable that some of the eggs she is sitting on are hers, so we will get some more Buffys. There is definitely a mixed bunch of eggs in there—17 hens, 2 different roos—so we will get a mixed breed bunch of chicks if any of the rest hatch.
The 2 chicks were out and about this morning, and mom had a hard time trying to keep an eye on them while still sitting on the remaining eggs (19 to be exact). I had to move the eggs, and then coax the chicks and momma into the dog crate which will be their home until most of the remaining eggs hatch, or don't.
It is still too cold at night to have chicks and/or eggs not under mom for warmth. Where they are now, at least they are all in one place, and no other hens can lay additional eggs in there. That's how we ended up with 21 total. Every time Momma left the nest box with the eggs, another hen would jump in there and lay some more.
A mother's work is never done...