In “The Secret Life of Walter Mitty,” the wife’s character is most developed by

exposition.

her thoughts.

Walter's words.

her dialogue with Walter.

The wife's character in "The Secret Life of Walter Mitty" is most developed through her dialogue with Walter. Through their exchanges, her personality, desires, concerns, and relationship with Walter are revealed, showcasing her development as a character. Exposition and her thoughts may provide some insight into her character, but it is primarily through her interactions with Walter that her character is fully explored and developed.