Kate was one of five children of Henry and Kitty Branston. She married 32 year old Frederick Johnson in 1893 in Affpuddle, Dorset when she was 29. They had six children which included three boys who all died in World War One. Other children: Lena Bateman (1895-1981), William Alan Johnson (1901-1950 d. Australia), Leslie Johnson (1902-1986)
Her husband died in 1941. Sometime in the early 1950s she was institutionalized in Roundway Insane Asylum in Devizes, Wiltshire where she died in 1957.
She is buried in the Roundway Insane Asylum cemetery. There is no marker as all the stones in that cemetery were removed.