Cooke worked as a governess in England for 20 years before applying to the Church Missionary Society (CMS). Assigned to Singapore, in 1853 she took over the Chinese Girls’ School, which had been founded in 1846. (It continues a century and a half later as the St. Margaret’s Girls’ School.)
Under Cooke, the school served as a home for abandoned or abused Chinese girls and as a base for evangelistic work among Chinese women. Several of its pupils went on to work for the CMS mission in Foochow (Fuzhou), China. Cooke was actively involved in social work on a wide scale. She was a founder of the Sailors’ Rest, fed and clothed sailors who were destitute or ill, and led Bible studies and worship for sailors, soldiers, and policemen.
Her weekly worship services for Chinese were the direct predecessor to the first Anglican and Presbyterian Chinese churches in Singapore. Cooke was also founder of the Singapore YWCA and helped organize branches of the Ladies’ Bible and Tract Society and the British and Foreign Bible Society. Through these agencies she played a leading role in mobilizing the European population of Singapore for Christian mission. In her projects she worked closely with Brethren, Presbyterian, Anglican, Wesleyan, and later Methodist missionaries in Singapore. She instituted and inspired extensive ecumenical social work whose legacy continues until today. She died in Singapore.