Harriet’s 16-year-old sister, Allison is quiet and introspective, often lost in sleep and dreams, revealing her struggles with the realities of growing up and processing loss.

Harriet’s older brother who died when she was a baby; his mysterious death deeply affects the family and becomes the focal point of Harriet's quest for answers.

Harriet, Allison, and Robin’s mother, who is overwhelmed by grief over Robin's death, struggles to connect with her children and remains largely withdrawn from family life.

The Dufresnes' longtime housekeeper who provides Harriet and Allison with care and affection, forming a significant emotional bond with them despite their family's lack of recognition of her importance.

Harriet’s grandmother, who is strong-willed and resourceful but often engages in revising family history to cope with the family's misfortunes, serving as a practical, though sometimes cold, figure in Harriet's life.

Harriet’s great-aunts, consisting of Libby, Tat, and Adelaide, who each contribute to the family dynamic by serving as additional parental figures for Harriet and Allison, with varying degrees of warmth and practicality.

Harriet’s best friend and companion in her adventures, who is eager to impress Harriet and often joins her in her plans, despite not fully understanding the risks involved.

A working-class family consisting of grandmother Gum and brothers Farish, Danny, and Eugene; their interactions with Harriet's quest present a mix of challenges and complications.