Browne joined
Sinn Féin in 1912 and the
Irish Volunteers in 1914 and flew a tricolour from her family home, Rathronan Castle, during the Easter Rising. She was arrested and imprisoned in Kilmainham and
Mountjoy prisons, along with her friend
Nell Ryan. She took the Pro-Treaty side during the Civil War, joining Cumann na nGaedheal. Ryan was
Anti-Treaty and their friendship did not survive the Civil War. She was elected to Seanad Éireann of the
Irish Free State as a Cumann na nGaedheal member, at a
by-election on 20 June 1929. The by-election was caused by the death of
Alice Stopford Green. She was re-elected for three years in 1931 and was re-elected for nine years in 1934. She joined the
Army Comrades Association, known as the
Blueshirts, in 1933. Browne claimed not be a
fascist, but had joined ranks with the ACA because she shared their Anti-Communist and
Republican viewpoints. Following the merger of the Blueshirts into
Fine Gael, she remained a part of the Fine Gael faction rather than continuing to follow
O'Duffy's ventures such as the
National Corporate Party. At this point she seemed to gravitate more towards the new Fine Gael leader
W. T. Cosgrave, who she became personal friends with. She served as a senator until 29 May 1936 when the Free State Seanad was abolished. == Historical and conservation activity ==