The 11-year-old eldest sibling of the three railway children. She is deeply sensitive, emotionally mature, and fiercely protective of her family's feelings. Her strong moral compass and desire to help others drive much of her interaction with the community, leading her to initiate contact with strangers who can assist her family.

A deeply loving woman who becomes the sole breadwinner for her family by writing stories and poems for various publications. She maintains a stoic, cheerful exterior to shield her children from the pain of their altered circumstances. Despite her sudden poverty, she retains her upper-class pride and initially resists accepting outside charity.

The middle child and only boy of the family. He struggles with the family's sudden drop in wealth, taking it upon himself to steal coal from the railway out of a misguided sense of duty. He keenly misses male companionship in his father's absence.

The youngest of the three children, who shares in her older siblings' explorations along the railway. She is generally good-natured and follows the lead of her older sister, though she frequently squabbles with her brother. She approaches their new countryside life with innocence and curiosity.

A noble and honorable man who works for the government. He is a loving parent whose sudden, unexplained departure shatters the family's idyllic London life. His absence creates a void in the household as the children relocate to the country and learn to survive without him.

A wealthy, elderly District Superintendent of the railway who regularly travels past the children's countryside home. He possesses significant social connections in London and responds generously to the children's written appeals. He becomes a vital benefactor figure to the struggling family.

A highly regarded Russian author who arrives in England seeking his lost wife and children. He suffered severe persecution and imprisonment in his homeland for writing about the poor. He finds temporary refuge in Mother's home while trying to locate his family.

A hardworking railway porter and devoted family man who works at the local station. He takes time to teach the children about trains and railway operations. He holds a fierce working-class pride and strongly resists anything he views as patronizing charity from his neighbors.

The local countryside doctor who tends to the family's medical needs. He is a practical man of modest means who agrees to treat the family at a reduced rate after learning of their financial struggles.

A young boy who participates in a local steeplechase race. He breaks his leg in a dark train tunnel, requiring a long convalescence that brings new dynamics into the children's household.

A rough-spoken bargeman who operates on the local canal. After an initial clash with the children over fishing rights, his attitude shifts dramatically when they intervene during a crisis on his boat.

The wife of the railway porter. Unlike her husband, she is immediately touched by and receptive to the thoughtful gifts the children gather for his birthday.

The authoritative figure at the local railway station. Though he strictly lectures the children about stealing coal, he ultimately demonstrates leniency and allows them to remain around the station.

A railway worker stationed near the tunnel. He falls asleep on the job and panics when the children wake him, fearing he will lose his employment.