The fourth falcon hatched sometime during the night of April 12-13. Reliable times to watch feeding, which is about the extent of activity in the nest right now, are about 6:30 a.m. PDT and 7 p.m. PDT. Those might change as light comes earlier and stays later.
I watched this morning. At 6:30 (8:30 here) almost to the second, George brought Gracie a hunk of something. She fed the chicks until about 6:47, then took off with leftovers, and George took over brooding the chicks.
It won't be long until they're too big for him to be of much help. Remember, he weighs about 650 grams to Gracie's 950 grams.