[1] Cahalan was described as one of the only women from a working-class background to have a major role in the Irish suffragette movement.

[3][4] In 1912 she headed the "Ladies Committee" of the Dublin branch of the IDAA, and also was a contributor to the journal run by the union.

[1] In the same year, she sought the support of the Dublin Trades' Council for women's suffrage, in her role as a delegate of the IWFL.

[1] From 1922 to 1923 she was also on the executive committee of the IDAA, but resigned in protest, citing the union's lack of action on imprisonment.

Cahalan had a well publicized debate with fellow suffragist Louie Bennett in 1919, over the subject of membership in trade unions.

[4] In an article in The Irish Citizen Cahalan acknowledged that women's entry into unions had led to antagonism from male workers due to lower wages.