The Lady in Black is a member of the vacationing party on Grand Isle but functions more as symbolic set-dressing than a fleshed-out character. The black she wears implies that she is a widow in mourning garb, and at every appearance she is engaged in religious devotion with a prayer book or rosary. Always walking a few paces behind the Lovers, the Lady in Black symbolizes mortality and consequences. While the Lovers completely ignore everything and everyone around them, the Lady in Black follows, and as the novel progresses, she appears to catch up to the Lovers, until she is “gaining steadily upon them.” Their strange procession is a reminder of the inevitable passage of time, of aging. The Lovers, who are so happy now, will someday grow old and be severed by death.
The Lady in Black’s constant religious occupations represent consequences and morality. While the Lovers pay no attention to what they are doing, the Lady in Black is hyper-focused on religious morality and the fate of her mortal soul according to Catholic doctrine. Although not as explicitly detached from reality as the Lovers, the Lady in Black nevertheless seems more focused on the future—her death—than her present at the beach. During the one time she participates in group conversation, she talks about buying rosary beads in Mexico, again focused only on religion. Implicitly this is the life that the ideal Creole woman, should she survive her husband, is destined for. She is self-effacing, and having no man left to devote herself to, devotes herself to God.