[4] In 1903, inspired by a pro-nationalist speech given by Maud Gonne, Molony joined Inghinidhe na hÉireann (Daughters of Ireland) and began a lifelong commitment to the nationalist cause.

[6] "Bean na hÉireann brought together a nationalist group; Constance Markievicz designed the title page, and wrote the gardening column; Sydney Gifford (under the nom de plume "John Brennan") wrote for the paper and was on its production team; contributors included Eva Gore-Booth, Susan L. Mitchell, and Katharine Tynan, as well as Patrick Pearse, Thomas MacDonagh, AE, Roger Casement, Arthur Griffith and James Stephens.

She was a very clever and attractive girl with a tremendous power of making friends.’[2] As a labour activist, Molony was a close colleague of Markievicz and of James Connolly, whose secretary she was for a time.

In the same account,[9] Molony describes leafletting O'Connell Street – then, on the GPO side, only frequented by British soldiers and their mots: "Misses Elizabeth O'Farrell and Sighle Grennan and myself were spotted by police.

Fianna Éireann, the cadet body of the Irish Volunteers, was founded by Constance Markievicz in Molony's home at 34 Lower Camden Street, Dublin, on 16 August 1909.

[16] Molony was a prominent member of Cumann na mBan, a republican women's paramilitary organisation formed in April 1914 as an auxiliary of the Irish Volunteers.

Members of Cumann na mBan trained alongside the men of the Irish Volunteers in preparation for the armed rebellion against the English forces in Ireland.