Who is a round character in the story "Lily Daw and the Three Ladies," and give three examples of how Welty developed the character you name.

Typically, when we talk about a "round character," we mean a character in a story that is fully developed. They feel like they have some reality to them, we learn a lot about them, and they are usually the ones who encounter an obstacle and are changed in some way because of it. The term "round character" is in contrast to someone we would term a "flat character." A "flat character" is someone that typically remains the same through the text and does not have many different facets or layers to uncover.
The characters in "Lily Daw and the Three Ladies" remain largely the same, but the characters that would make the best case for a round character are Aimee and Lily.
While Aimee does not appear to change very much throughout the text, she is the one who makes the discovery that Lily's marriage is real and rushes around trying to help Lily and her prospective lover. The reader gets more emotion from Aimee than from the other women, and we are told that "Aimee cried sorrowfully, as she thought how far away it was" (Welty). Aimee is also the one who faces the conflict most directly, as she discovers the identity of the man that Lily plans on marrying and has to try to stop the train. At the end, it is Aimee again who realizes that Lily has left her hope chest on the train, and she feels sadness for her.
Lily also does not appear to undergo significant change, and she does not speak very much for herself. However, she gets the reader's real sympathy because of the way she is pushed around. When the other women come to tell Lily she is going to Ellisville, she is pathetically packing her tiny hope chest. When the women discover that the man is real and try to get Lily off the train again, Lily begins to cry and is confused at the change that the women have now pushed her into. Finally, when she does reunite with the man she spoke about, he "kisse[s] Lily with a smack, after which she hung her head" (Welty). The reader gets the sense that Lily is pushed into one situation after another without really understanding or enjoying her circumstances, and she is the most sympathetic figure in the story.
https://archive.nytimes.com/www.nytimes.com/books/first/w/welty-stories.html?_r=1