The female has spent most of today watching over her first egg!  She has dug for tight incubation, she has been out of the nest box, and she has been just getting used to having an egg, and knowing more eggs are likely to follow soon.  Sometimes she completely covers the egg and other times, like this, she hovers over, but does not fully cover the egg.

In this next photo, she shows herself hunkered down, much more on top of the egg, with her tail down low and wings slightly elevated