Nice, that is extremely fast. They are cute looking too!
I had a Solenopsis xyloni queen get workers in 2 and a half weeks. Wasn't even three weeks, and next thing I know there were workers. That was the fastest I ever got workers from any queen. No idea how she got workers THAT fast, but I was keeping them MUCH warmer than usual (it was summer and my room was very hot at the time).
Still, 3 weeks is very fast when the average time is over a month. And looks like a lot of workers eclosed almost all at once! Grats.