A sickly child, Johnson did not attend Brantford's Mohawk Institute, a residential school established in 1834. Her education was mostly at home and informal, derived from her mother, a series of non-Native governesses, a few years at the small school on the reserve, and self-guided reading in her family's expansive library. She read deeply in the works of Byron, Tennyson, Keats, Browning and Milton, and enjoyed reading tales about Indigenous people such as Longfellow's epic poem "The Song of Hiawatha" and John Richardson's "Wacousta". These informed her own literary and theatrical work.