I've been gone on a road trip for 2 weeks so I was particularly anxious to see how the Family had progressed --- and to be sure that all 3 nestlings had survived. They had and boy, have they grown...
First, some background on "fledging" as I too was unsure what it actually means. It's from the Middle English "flegge" meaning "feathered" and refers to the development of a nestling's flight feathers. To quote Marie Winn writing in the excellent "Red-tails in Love" --- "Since the first flight inevitably follows a bird's complete feather development, fledging and first flight are virtually synonymous". As the first baby was born around April 10 (all 3 eggs hatch at 1-2 day intervals) and they are fully fledged (the males before the females) around 45 days from hatching, we may see the first serious attempts at flying during the week of May 23.