Okay, it's time to play, "Just How Stoopid Can She Be?" (Answer: epically, incredibly, voluminously stoopid.)
After treating my mite-ridden broody, she wouldn't go back on her eggs. I put the eggs under another accommodating hen. When the mitey broody started sitting on different eggs in the second story of nest boxes an hour later, I wanted to give her her own eggs back . . . but couldn't figure out a way to do so that would be clean and safe for possible chicks as she wouldn't go in the lower boxes.
Maybe a dog crate in the coop? Or try a lower nest box again?
Or . . . . .
MAYBE USE THE BROODER MY HUSBAND SO LOVINGLY BUILT FOR ME???????
[COLOR=0000FF]D'OH![/COLOR]