Early in life Watney dedicated herself to missionary work, and for this purpose trained as a nurse.
Watney was accepted by the CEZMS (Church of England Zenana Missionary Society), a mission which started in India but spread to China.
She was Principal of the Church of England Zenana Mission School for Blind Girls in Nantai.
She died on 10 January 1958 at the Oxted and Limpsfield Hospital, and was buried in Westerham, Kent.
Her niece, Faith, was a missionary with CMS in Sudan, and married Leonard Sharland.