Hopkins co-founded the White Cross Army in 1883, and vigorously advocated moral purity while criticising contemporary sexual double standards.

[1] In 1874 Hopkins and rescue worker Sarah Robinson established the Soldier's Institute at Portsmouth, and in 1876 toured several British towns, recruiting thousands of women to the Ladies' Association for the Care of Friendless Girls.

[3] Hopkins wrote in a wide variety of genres, including two volumes of poetry, English Idylls (1865) and Autumn Swallows (1883), and a sensational gothic novel, Rose Turquand (1874).

She wrote pamphlets, most notably True Manliness (1883), and Christian devotional works,[6] including Christ the Consoler, A Book of Comfort for the Sick (1879), and A plea for the wider action of the Church of England in the prevention of the degradation of women, an essay in which she criticised the contemporary double standard by which women were disproportionately blamed for sexual immorality.

[1] Her last books were The Power of Womanhood (1899), on the role of mothers in "moral evolution",[3] and The Story of Life (1902), a guide intended to help parents teach sex education to their adolescent children.