It was around 11:25AM when I noticed Sadie get restless and unsettled on her egg. She looked uncomfortable and was showing signs that she was going to lay another egg. Her breathing accelerated, she hovered over the nest bowl, and within a few minutes she had laid her second egg. The whole process took just a few minutes, around the same amount of time it took for her to lay her first egg.
A screenshot I took at 11:29, shortly after her 2nd egg appeared in view on the live nest cam:
At 11:48: