Sybylla is a hypersensitive, intelligent thirteen-year-old tomboy growing up in rural New South Wales who dreams of pursuing a career in writing or music. She possesses a fierce independent spirit and a sharp tongue, struggling against a local culture that views marriage as the only achievement for young women. Though she views herself as physically plain and doomed to a humdrum life, her quick mind and singing voice draw unexpected attention when she is sent to live at her grandmother's Caddagat estate.

Harry is the tall, sunburned, and wealthy scion of the neighboring Five-Bob Downs farm. He projects a cool confidence and maintains a notably quiet demeanor, contrasting with the chaotic energy of Sybylla's world. Though he possesses traditional gentlemanly skills like piano playing and horse management, he harbors a notoriously quick temper and views romance through a strict lens of ownership.

Dick is a jovial and initially optimistic station agent who relocates his family to 'Possum Gully to establish a sheep farm. He is a loving father who acts as an encyclopedia and hero to young Sybylla, but his happy-go-lucky nature leaves him deeply unprepared for the brutal realities of drought and cutthroat agricultural economics. His inability to manage the farm's finances leads to mounting debt and a heavy reliance on alcohol.

Lucy is the gentle and hospitable matriarch of the spacious Caddagat estate. She provides Sybylla with a temporary sanctuary from the poverty of 'Possum Gully, offering access to a large library and a more refined social circle. While she is endlessly patient with her granddaughter's dramatic mood swings, she strictly maintains the conservative views of her era regarding a woman's proper domestic role.

Helen resides at the Caddagat estate with her mother after enduring the public humiliation of being abandoned by her husband for a younger woman. Rather than retreating into bitterness, she actively mentors Sybylla, attempting to soften her tomboyish presentation into refined grace. She provides crucial philosophical advice, encouraging her niece to seek genuine friendship and respect rather than fleeting romantic passion.

Sybylla's mother is a pragmatic and exhausted woman burdened by the slow collapse of the family's 'Possum Gully farm. She worries constantly about Sybylla's rebellious attitude and plain appearance, fearing these traits will make securing a financially necessary marriage difficult. Her approach to parenting is highly critical, prioritizing survival and practical labor over her daughter's artistic ambitions.

Gertie is the younger daughter of the Melvyn family. She is conventionally attractive, sweet-natured, and possesses the innocent coquetry that aligns perfectly with the societal expectations of young Australian women, standing in sharp contrast to her older sister's rebellious nature.

Everard is the gallant, aristocratic family attorney who visits the Caddagat estate. As an educated city man who dabbles in poetry and sketching, he recognizes Sybylla's exceptional singing voice. He offers to secure her a talent agent and provides the artistic encouragement she so desperately craves, though his romantic advances feel abrupt.

Frank is a young man managing the livestock at the Caddagat estate who expects to inherit his family's farm in England upon turning twenty-four. He approaches courtship with a blunt, business-like efficiency and entirely fails to understand Sybylla's artistic temperament, viewing her simply as a suitable candidate for his future household.

Julius is a district magistrate who lives with his mother and sister at the Caddagat estate. He is a respectable authority figure who quietly observes the household dynamics and occasionally offers Sybylla pointed warnings about the temperaments of her local suitors.

Peter is a dirt farmer operating a small, unrefined property in the remote, sweltering region of Barney's Gap. He holds a substantial, unpaid debt over Dick Melvyn, leading to Sybylla's arrangement to work as a governess for his family. He possesses a rough-edged decency and a practical work ethic, though he completely lacks cultural refinement.

Mrs. M'Swat is the overworked and perpetually exhausted mother of nine children living in a cramped, tin-roofed house in Barney's Gap. She struggles to maintain order in a chaotic environment overrun by farm animals and heat, relying on cheap popular magazines for her only source of entertainment.