One more thing was unusual -  her left arm. Her forearm narrowed to the wrist then widened a bit, ending abruptly in a few nubbins. I never did figure out whether her arm ended right at the wrist or just below it in the heel of a hand - not that it mattered.

I sat on one of the benches nearby for a while to see what would happen. From time to time a customer would come along and buy a donut or two in a paper bag. The girl would put the donuts in the bag with a pair of tongs, anchoring the bag steady by gripping its lip between her nubbins. Apparently she had some control over them. None of her customers seemed to notice, or if they did, it didn't seem to bother them.

Finally I went on with my shopping. It brought me back past the booth several times. The scene was always the same, The boys continued to talk to her and the occasional customer bought some donuts. The last time I went by, an elderly man with a shy smile on his face was there buying a couple of donuts - for the third time that afternoon.