The daughter of a radical Member of Parliament, Clark was a prominent speaker for women's voting rights and at times a political realist who served as a mainstay of the 19th century suffrage movement in South West England.

[2] A liberal in all senses,[1] Clark aided progress toward universal human brotherhood through her activities in organisations which assisted former slaves and aboriginal peoples.

"[1] In 1866 as Helen Bright she signed the "Ladies' Petition" on suffrage being circulated by Elizabeth Garrett and Emily Davies, as did her former teacher Hannah Wallis.

[1] Clark spoke publicly for the first time in 1872, giving a lecture in Taunton during a meeting organised by the Bristol and West of England National Society for Women's Suffrage.

"[1] On 9 March 1876 in the Victoria Rooms, Clifton, Bristol, Clark spoke strongly for the removal of the voting disabilities of women, in support of a parliamentary bill to that end introduced by a Mr. Forsyth.

Though Bright was considered a Radical and a Liberal, and though he had accompanied Mill during the presentation of the Ladies' Petition to the House, he was never personally in favour of women voting.

Clark sided with Lydia Becker and her supporters who backed the couverture clause introduced by William Woodall to the Liberal Reform bill.

Clark gave her support on the grounds that this not wholly satisfactory clause had more chance of passing and could subsequently be used as a wedge by which women's suffrage could be expanded.

[10] In February 1900, she protested that the Methodist Times claimed that her father would have been a supporter of the Boer War, and wouldn't publish her response that instead he would have been an advocate for peace.

[11] In 1914 as war was mounting in Europe, Clark joined the International Woman Suffrage Alliance (IWSA), a group of women who sought voting rights, most of whom advocated world peace.

Clark signed an "Open Christmas Letter" addressed "To the Women of Germany and Austria" which was published in IWSA's Jus Suffragii in January 1915.

[12] Among the other 100 signers were Margaret Ashton, Emily Hobhouse, Sylvia Pankhurst and a wide range of women united by the wish for a quick end to hostilities.

[12] The letter was a plea for world peace among women, and was answered in kind by 155 Germanic feminists including Anita Augspurg, Lida Gustava Heymann and Rosa Mayreder.

[13] In the 1860s, Clark became active in the UK branch of the Freedman's Aid Society which sought to assist former slaves in establishing basic yet comfortable homes.