She was born in 1858 at 38 Lower Kennington Lane in Kennington, Surrey (now part of Greater London), the daughter of a schoolteacher, John Collis Nesbit, who died in March 1862, before her fourth birthday. Her sister Mary's ill health meant that the family moved around constantly for some years, living variously in Brighton, Buckinghamshire, France ( Dieppe, Rouen, Paris, Tours, Poitiers, Angouleme, Bordeaux, Arcachon, Pau, Bagneres de Bigorre, and Dinan in Brittany), Spain and Germany, before settling for three years at Halstead Hall in Halstead in north-west Kent, a location which later inspired The Railway Children. When Nesbit was 17, the family moved again, this time back to London, living variously in South East London at Eltham, Lewisham, Grove Park and Lee. A follower of William Morris, 19-year-old Nesbit met bank clerk Hubert Bland in 1877. Seven months pregnant, she married Bland on 22 April 1880, though she did not immediately live with him, as Bland initially continued to live with his mother. Their marriage was an open one. Bland also continued an affair with Alice Hoatson which produced two children (Rosamund in 1886 and John in 1899), both of whom Nesbit raised as her own