Fraser joined the Women Social & Political Union in 1906 after hearing a speech made by Teresa Billington-Greig. She became treasurer of the Glasgow branch of the WSPU and was responsible for recruiting Janie Allan to the organisation in 1907.
In early 1907 she and Adela Pankhurst organized the WSPU campaign at the Aberdeen South by-election. She later recalled: "It was winter and very cold. I met her at the station and was horrified at her breathing. I took her to lodgings and sent for the doctor, who, like me, was very critical of her being allowed to travel. She had pneumonia." The campaign was a success and the Liberal Party majority of George Birnie Esslemont was reduced from 4,000 to under 400.
During the summer of 1908 the WSPU introduced the tactic of breaking the windows of government buildings. On 30th June suffragettes marched into Downing Street and began throwing small stones through the windows of the Prime Minister's house. As a result of this demonstration, twenty-seven women were arrested and sent to Holloway Prison. Helen Fraser disagreed with these "violent tactics" and resigned from the WSPU.
Soon afterwards Fraser joined the National Union of Suffrage Societies and was active in the Glasgow and West of Scotland Association for Women's Suffrage. Fraser was a very impressive speaker and the records show that in the year 1908-09 the sums collected for the NUWSS at her meetings amounted to £56.19.10.
Two days after the British government declared war on Germany on 4th August 1914, Millicent Fawcett declared that it was suspending all political activity until the conflict was over. Although the NUWSS supported the war effort, it did not follow the WSPU strategy of becoming involved in persuading young men to join the armed forces.
During the First World War she worked for a time for the National War Savings Committee before joining the Board of Agriculture where she was given the task of persuading women to work on the land. She later published the book, Women and War Work. In 1917 she was sent to the USA to speak on Britain's war effort. During her lecture tour she spoke 332 times in 312 days.
After the passing of the Qualification of Women Act the NUWSS and WSPU were disbanded. Helen Fraser joined the Liberal Party and was the unsuccessful candidate for Glasgow Govan in the 1922 General Election. Helen Fraser married and in 1939 emigrated to Sydney, Australia, where she was reunited with Adela Pankhurst.
Helen Miller Fraser died in 1979.