Harriet and her mother returned to England in 1857. In 1858, Harriet Mills married Alfred Robert Roche. The couple traveled to the Transvaal in 1875, but became ill. Mr. Roche died during their return voyage. Harriet Roche married her second husband, Rev. Micail or Michael Boomer, of the Diocese of Huron, Ontario, Canada in 1878. She published two books about her experiences: "On Trek in the Transvaal; or, Over Berg and Veldt in South Africa" (1878) and "Notes From Our Log in South Africa; and, On Foot Through the Colonies At the Paris Exhibition" (1880).