Caroline Sybil Ryrie born in Moscow, Idaho, the only child of Alexander and Henrietta (Watkins) Ryrie. Her father, an immigrant from Scotland, was the city's mayor (1895–97) and her mother was the daughter of prominent physician Dr. William W. Watkins, the first president of the state's medical association and a member of the board of regents of the new University of Idaho. After Alex Ryrie died in 1900, Henrietta remarried, but after her father was murdered in 1901, her second marriage (to Elisha Nathaniel Brown) failed and she committed suicide in 1904 at age 29. Carol was then raised in Moscow by her widowed maternal grandmother, Caroline Woodhouse Watkins, the model for Caddie Woodlawn. They moved to Idaho in 1907, three years before statehood, when Carol was twelve, and her grandmother's life and storytelling abilities inspired Carol's writing from an early age.