Let us remember that a round character is the opposite of a flat character, in that the character is presented in his or her full psychological complexity, with a number of different characteristics. By contrast, a flat character is not fully developed and only has one or two notable characteristics. A dynamic character is the opposite of a static character, and is a character that changes during the course of the tale.
If we examine the character of Elisa in this brilliant story, it is evidently clear that she is a round character, as we are presented with her character in all of its complexity. Note how the following speech by Elisa reveals her curious longing and also her loneliness:
Elisa's voice grew husky. She broke in on him: "I've never lived as you do, but I know what you mean. When the night is dark--why, the stars are sharp-pointed, and there's quiet. Why, you rise up and up! Every pointed star gets driven into your body. It's like that. Hot and sharp and--lovely."
This definitely reveals a complex character. However, when we consider if Elisa changes through the course of the story, it becomes more complicated. It is clear that she is left in her hopeless and lonely position at the end of the story, feeling trapped in her life and married to a husband who, while good, fails to understand her. The visit of the tinker only serves to highlight Elisa's own sense of loneliness and despair. Even the connection she feels she has established with him is shown to be false, as the chrysanthemums he has discarded shows. Elisa is therefore a static character, that does not experience any massive changes in herself through the course of the story.
Usually, the main characters is a dynamic/round character due to conflicts that occur throughout the story. But i have read stories in which the main character is barely characterized, and can only be described as a static/flat character.