Nuthatches Must Be Near Hatching

The White Breasted Nuthatches are well along in their first wave nesting in their favorite box.  I've seen the male feeding the female often in recent days, so she's clearly inclined to stay put.  She's also alert. I caught this photograph while checking for Jack in the Pulpits in the area below.  She didn't seem irritated, merely concerned.  Once I took the photo I backed off and left her in peace.  That visit also confirmed that the fledge hasn't taken place, and probably not the hatch either (else she'd be feeding the young).  So how long a wait?  Can't be more than a few more days.  We will be waiting!