Margaret Mary Pearse, Fianna Fáil politician and teacher, is born on August 24, 1878, at 27 Great Brunswick Street (now Pearse Street) in Dublin. She is a sister of Patrick Pearse, one of the leaders of the 1916 Easter Rising, and Willie Pearse, both of whom are executed for their part in the Rising.

Pearse is the eldest child of James Pearse and Margaret Pearse (née Brady), who serves as a Teachta Dála (TD) in the 1920s. She is educated at the Holy Faith Convent in Glasnevin. After leaving school, she trains as a teacher. She helps to found St. Enda’s School with her brothers Patrick and Willie. Following the executions of her brothers in the aftermath of the Easter Rising, she continues to run St. Enda’s, along with Fergus De Búrca, until 1933.

Following in her mother’s footsteps, Pearse is first elected to Dáil Éireann as a Fianna Fáil TD for the Dublin County constituency at the 1933 general election. She is defeated at the 1937 general election on the 7th count of votes but is elected to the Administrative Panel of the 2nd Seanad. She serves in the Seanad until her death in 1968, however, she and her mother are never considered to be more than figureheads for the party. She is a founding member of the teaching staff of Ardscoil Éanna in Crumlin, Dublin, upon its establishment in 1939.

Illness forces Pearse into the Linden Convalescent Home in Blackrock, County Dublin when she is in her 80s. In 1967, when she is 89 years old, her condition is described to be deteriorating. However, in 1968 during the months leading up to her 90th birthday, she leaves the Linden Convalescent Home for a short while in order to spend her birthday at St. Enda’s in Rathfarnham. The president of Ireland at the time, Éamon de Valera, visits her at St. Enda’s to congratulate her on her upcoming 90th birthday.

Margaret Pearse dies, unmarried, at the Linden Convalescent Home in Blackrock, County Dublin, on November 7, 1968, and is given a state funeral. President de Valera, the church and the state all pay tribute to her at the funeral. She is buried beside her parents and sister at Glasnevin Cemetery. The Taoiseach, Jack Lynch, says that Margaret Mary Pearse is the last remaining member of the noble Pearse family. He says her life, like her patriotic brothers, was dedicated to Ireland.

As per her mother’s wishes, Pearse bequeaths St. Enda’s to the people of Ireland as a memorial to her brother’s sacrifice. The school is now home to the Pearse Museum.