In literature, the mockingbird symbolizes innocence, purity, honesty, which I see in Edna’s accomplishing the duty which her mother and wife roles assume.
By making a parallel between Edna and the mockingbird, I’d like to point out the fact that the author wanted us to see Edna’s changing, from the honest, innocent woman who is taking care of her family in the first part of the story, to the woman who loses interest in her mother and wife roles in the second part. In her moment of uncertainty, after she learns to swim and lives her moment of awakening, bit by bit she starts to lose her honesty and her love towards her own family. Her awakening is not only sexual in part but also a search for creativity, through her skills of painting.
Edna was encouraged to defy society’s expectations and roles by Mademoiselle Reisz and to act as a bird, even checking her ‘wings’ in a hug: “she put her arms around me and felt my shoulder blades, to see if my wings were strong, she said. ‘The bird that would soar above the level plain of tradition and prejudice must have strong wings.” (page 88)