Thanks to sharp observers Donna Memon and @PittPeregrines here's a photo of Dorothy's third egg, laid today at 5:35pm.
I'm glad the heat wave is over! Dorothy is too, I'm sure.
Just over an hour later: A photo of the three eggs as E2 leaves the nest to switch egg-duty with Dorothy:
(photo from the National Aviary falconcam at the Cathedral of Learning)