Single Nestling Ready to Make It's Virgin Flight~

I visit my father-in-law some 25 miles from our home at least twice a week.  He has been thrilled that House Wrens used his nest house near his kitchen window, but also that an American Robin pair took over an old nest and raised one single chick.  The nestling was really quite large when I saw it last and seemed so ready to get out of the nest and move in other directions~