It was a pure fluke (well not completely pure because obviously I knew we were in the window). I had waited on Sunday for the best weather to make my rounds, had just finished the second A/S of the year and was getting ready to wrap up, around 4:20. It was about 19C in the shade, but the entrance was in sunshine and the apiary was warmer.
I noticed a fuss around the entrance of the Q-"insurance" nuc I had on the roof of the main Q- half. So she was in a nuc, on a roof. The fuss gets louder, Nasonov fanning starts, a bunch of drones come out so I decide to stick around and sure enough, out she comes, falls flat on her back, picks herself up and flies off. A nice-looking Q, to my inexperienced eye. Fool that I am, I missed the return, which means she was back in 15 mins.