In 1911, after returning to Scotland from India she worked for women's rights in Dundee as a member of the militant Women's Social and Political Union. In December 1912 she was imprisoned at Perth Prison for smuggling herself with others into the Music Hall Aberdeen. They had intended to disrupt a Liberal meeting with the then Chancellor of the Exchequer, David Lloyd George. She was imprisoned at Perth under the name Marion Pollock. Throughout 1913 and 1914 she wrote many letters to the press and was regularly removed from public meetings for being disruptive. Disguised in widow’s tweeds and glasses, she managed to get into a Labour meeting held by Ramsay MacDonald in the Gilfillan Memorial Hall, but was roughly dragged out by eight burly men – an onlooker describes this as "one of the strongest arguments for women’s suffrage that I have ever seen."
At the outbreak of war in 1914 she enlisted as a nurse with the Voluntary Aid Detachment at Caird Hospital, Dundee. In 1916 she joined Margaret Damer Dawson's Women Police Service, working first in a munitions factory and then serving in London as a Constable, then a Sergeant and, by 1918, had reached the rank of Sub-Inspector. She left the organisation at the end of the war.
Political career
After the war Grant became involved in politics and joined the Liberal party. To go from suffragette to policewoman to Liberal politician was a path also trodden by Mary Sophia Allen. By 1922 she was spending much of her time as a public lecturer on politics and social problems. She was then selected as a David Lloyd George supporting Liberal candidate for Leeds South East constituency for the general election. Her opponent was the sitting Labour MP James O'Grady who had been returned unopposed in 1918. As there was no Unionist candidate she polled a strong vote but did not win. After the Lloyd George and H. H. Asquith wings of the Liberals re-united, she stood as Liberal candidate in Pontefract, where the Liberal candidate had come third in 1922. Once again it was a three-cornered contest and Grant was unable to avoid a squeeze on the Liberal vote; She did not contest the 1924 General Election. By July 1928 she was selected as Liberal candidate for Salford West, another Labour/Unionist marginal where the Liberals were not expected to do that well. She again finished third.
