Nancy married the poet Robert Graves in 1918. The following year he started as a student in Oxford, and they lived in a cottage on Boars Hill, rented from John Masefield. In 1920, in partnership with a neighbour, The Hon. Mrs Michael Howard, she set up a small grocer's shop, next door to the Masefields' house. Alarmed by the tourists it attracted, Mrs Masefield opposed its takeover by an Oxford firm, and the project collapsed after 6 months, leaving heavy debts settled only with the help of friends and family. In disgust, Graves and Nancy moved to the village of Islip, the other side of Oxford.
A life-long feminist, Nancy used to cycle to Oxfordshire villages and set up a stall to explain to women - illegally - how to use contraception. Her open-mindedness led her to accept a triangular relationship, and from early 1926 Laura Riding lived with her and Graves in London The marriage eventually broke down, as Graves increasingly favoured Riding, leaving Nancy to bring up the four children of the marriage alone, in a succession of locations, including Cumberland and a further spell on Boars Hill. They were divorced in 1949.
After a period in the early 1930s living with Geoffrey Taylor on a houseboat moored in Hammersmith, Nancy set up the Poulk Press, in which she collaborated for a time with him. They lived near Sutton Veny, Wiltshire, in a timber house designed by Nancy and built with family labour. Her relationship with Taylor lasted five years. She worked at this period with Ben and Barbara Hepworth on textiles.
Undeterred by the failure of the Boars Hill shop, in the 1940s she ran a business in Motcomb Street, London. Her designs influenced her sister-in-law EQ Nicholson. Her work was exhibited at the Victoria and Albert Museum in 1976.