Lane-Claypon was born Janet Elizabeth Claypon in 1877 into an affluent family, in Boston, Lincolnshire, the daughter of william Ward Lane-Claypon, a banker and former first-class cricketer, and Edith (née Stow). Her uncle C. G. Lane was also a first-class cricketer. A few weeks after her birth, her father changed the family name to Lane-Claypon by royal licence.