Arrived at nest at about 10:00 AM today and watched for about 20 minutes. The new female was roosting just above the nest to the right and the male appeared to be picking at sticks. There was quite a bit of finer grasses such as nest lining material. Note that the female is resting on one foot, with the other hanging and clenched.
The male then flew up and roosted just above the female.
Then the male flew back down on the nest and the female immediately joined the male.
There was a brief "recognition ceremony," as they touched bills.
Then they both started moving sticks, sometimes appearing to work together to move a large branch from the middle of the nest to the left rim. For a while the male just sat deep to the left and behind the female, almost invisible while she just stood on the nest.
Note the comparison of their face patterns (male on left). The female's gape does appear to reach a bit farther under her eye, about halfway. Her forehead is higher and her brow ridge may be a bit lower in front of her eye than that of the male (giving her more of a "frown"), and her head is more round vs the angular appearance of the male.