The cheerful organiser

Original fiction extract.

Only four people had arrived for the board-game evening, and two were volunteers. I began putting the spare chairs away. Our organiser remained buoyant. She said four people could play properly, make suggestions and help decide the next evening’s invitation. Her cheerfulness did not produce another guest, but it made the room feel less like a failed experiment. We played until nine. On the way out, she asked each visitor which game they would bring next time. I left the remaining chairs where they were.

Use your own words to explain what the word “buoyant” means in this extract.