What happens to Polly at recess and how do Leland and Lenora help her?

At recess, two boys anger Polly so much that she loses her temper and speaks sharply to them, but suddenly lapses into croaking. Before it can get worse, though, Leland and Lenora pull her to one side, and Lenora offers an idea - that Polly only croaks when she loses her temper.