In 1866, after she had taught for several years, Isabella was invited by her brother James Mills Thoburn, a Methodist Episcopal missionary in India, to assist him in his educational and missionary work in India. She delayed her departure until 1869 when the formation of the Women's Foreign Missionary Society of the Methodist Episcopal Church enabled her to undertake missionary work under denominational affiliation and auspices.[1]
^Keller, Rosemary Skinner, Rosemary Radford Ruether, and Marie Cantlon. Encyclopedia of Women and Religion in North America: Women and religion: methods of study and reflection. Vol. 1. Indiana University Press, 2006, pp. 824-38.