Born Rosina Ellis in Putney in London, Smith moved with her family first to Clay Cross and then Chesterfield in Derbyshire, where she won a scholarship to attend secondary school.
[1] Smith joined the Social Democratic Federation (SDF) in about 1910 and, the following year, attended a course on political science run by the Workers Educational Association (WEA).
[1] Around this time, Smith moved to Mansfield in nearby Nottinghamshire, where she joined the Socialist Labour Party, the local branch then led by John Lavin and Owen Ford.
[6] Smith and her husband had drifted apart, and the two separated in 1930; she moved with the children to Burnley in Lancashire, hoping to organise women involved in local textile work to join the Minority Movement.
She was selected to stand for the party in the Burnley constituency at the 1931 general election, but was arrested after supporting pickets during a strike and sentenced to three months in prison.