Her local priest at home was an Irish Republican Brotherhood activist, Fr James O'Daly, who let her know the plan for the rising Easter 1916.

Due to the confusion caused by Eoin MacNeill on Easter Sunday, the mobilisation planned for Tyrone was abortive.

Walsh remained involved in nationalist activities for the next few years and eventually had to quit her teaching position by 1919 because of harassment for her politics.

[1][2] Having returned home to Clogher from Belfast, Walsh was appointed by Tyrone County Council as their first woman rate collector in 1921.

When her family home was raided by the Royal Ulster Constabulary there were a number of documents found which were allegedly sedition and she fled Northern Ireland and moved to Dublin that month.

[1][2] In Dublin by December 1922 her qualifications allowed Walsh to get a position as a children's library assistant librarian in Rathmines.

[1][2][9][10][6][11][12] Walsh continued to be a national activist using her home to launch the new party Saor Éire as well as working on the editorial board of The Bell with Peadar O'Donnell.

She was a regular speaker at the meetings of the Women's Social and Progressive League founded by Hanna Sheehy-Skeffington and with Mary Hayden and Maud Gonne MacBride.