Characters and their role in The Last Leaf by O Henry?

Johnsy, suffering from pneumonia, is a character in The Last Leaf. She watches as the leaves from a vine outside her window falls, and thinks that when the last leaf falls she will die. Sue is Johnsy's friend who stays with her and offers comfort. Behrman is Johnsy's artistic downstairs neighbor, who braves a storm to paint a leaf on the wall so that Johnsy will never see the last leaf fall.