I made a quick trip out to the RFK Bridge and the Unisphere on Friday. The RFK female was feeding young, but they didn't pop up into sight, so I stuck out again in my attempt to get a glimpse at them.
The female at the Unisphere was sitting on the nest. It was impossible to tell if she was still sitting on eggs or had hatchlings. The nest is recessed into an I beam, which makes it a great hiding place for youngsters.
I'll be checking back up on these nests in a few weeks.