Grace Jones is a member of the wealthy Jones family and the younger sister of William Jones, the male protagonist of the story. As the eldest daughter, she holds a position of responsibility within the household and often assumes a maternal role, particularly with her younger siblings, such as calming Colin when he is upset. She is described as a capable and beautiful young woman, embodying the ideal of a proper Victorian lady through her classy, gentle, ladylike, and graceful demeanor.

In her social life, Grace maintains a close friendship with Eleanor Campbell, a young woman of similar social standing. The two are frequently seen together at social events like salons, receptions, the theatre, or the opera. Her strong sense of propriety and loyalty to her friend are central to her motivations. When she learns that her brother William has broken off his engagement to Eleanor, she reacts with shock and strong disapproval, even stating that his actions disgust her. Her anger intensifies upon discovering that William brought a maid named Emma to the family mansion, as she correctly deduces that Eleanor was used as a distraction and William was never serious about the engagement. This incident highlights her protective nature and her commitment to social decorum, leading her to distance herself from her brother for a time. Grace personally disapproves of William's relationship with Emma, which further complicates her perception of his choices.

Throughout the story, Grace is perceptive enough to notice changes in William's attitude, such as when he throws himself into work, though she does not always know how to approach him about it. Despite their conflicts, she remains a part of his life. Notably, Grace herself has a sympathetic and pleasant suitor to whom she has pledged to marry, although she has not yet introduced him to her father early in the narrative. She ultimately marries before her brother William, and by the time of his and Emma's wedding, she has already given birth to a son.