Today I dropped by the school (unannounced) to have lunch with the boys. When I stopped by the twins' room, their teacher said, "Look at this" and pointed to G. He was sitting at a study carrell, working all on his own. No aide, no ABA therapist holding a tiny piece of Oreo. He was just working for the sake of working!
Also, they said that during calendar time, G. had suddenly said, "Break time" (something they have been having the twins request with a voice output device). It was the first time he'd said it, so they let him take a break. I bet he'll learn that skill pretty quickly!
There are a few issues with ratios and also communication between school and home, but G's working without needing a reward is wiping that out of my mind for the moment.