O'Brennan, Elizabeth (‘Lily’) (1878–1948), republican, was born probably in Dublin, third daughter of Francis Brennan , auctioneer, and his wife, Elizabeth. The family was strongly nationalist and later changed their name to O'Brennan; her father was allegedly a Fenian and her sister Áine (qv) married Éamonn Ceannt (qv). Lily worked as a schoolteacher and contributed regularly to Irish and American periodicals. About 1912 she wrote a play, ‘May eve in Stephen's Green’, inspired by the statue of Mangan standing in the Green, and produced it, with Máire Nic Shiubhlaigh (qv), another republican, at the Father Mathew Hall, where it got good reviews. She was present at the inaugural meeting (April 1914) of Cumann na mBan, held in Wynn's Hotel, Abbey St., Dublin, and was made a member of the central branch. Six months later, after Redmond's declaration of solidarity with the English war effort, Cumann na mBan split and Lily and Áine sided with the anti-Redmond minority. Eighteen months later both were involved in plans for the rising; in the week leading up to it Lily bought tricolour bunting at a shop on Eden Quay to make a flag for the 4th Battalion of the Volunteers, and also carried dispatches for Ceannt. On Sunday she and Áine made up first-aid kits and assembled equipment, but it was only late that night they learnt that mobilisation would take place the following day. Ceannt's 4th Battalion had responsibility for the south-west Dublin area; O'Brennan was stationed in one of the outposts, in the distillery in Marrowbone Lane, where she remained all week, under the command of Con Colbert (qv). She and the other members of Cumann na mBan procured and prepared food and assisted with their first-aid skills.
At the Cumann na mBan convention in autumn 1917, O'Brennan was made an executive member, and the following year she toured Longford and Wicklow in a vigorous recruitment drive. At the convention that year, she seconded a motion for a weekly Cumann na mBan newspaper, but this was felt to be impracticable because of wartime shortage of paper and censorship. In 1921 she was on the secretarial staff of the treaty delegates and lived for the negotiation period in 22 Hans Place, Brompton, London, where she was apparently indispensable. In January 1922 she was briefly secretary to Arthur Griffith (qv). During the civil war she was on the staff at the republican headquarters in 23 Suffolk St. and was arrested there during a raid in early November 1922. Sent to Mountjoy, she joined in a protest against the detention of republicans with common convicts, and was among the first group of women to be transferred to Kilmainham on 6 February 1923. She spent three months in Kilmainham and helped organise the commemoration (24 April) of the seventh anniversary of the rising. Her spirits were unflagging; a fellow inmate described her as ‘rather diminutive and full of humour’ (Buckley, 68). She was moved in May to the North Dublin Union, where she took part in an abortive escape attempt, before being released a few weeks later. Thereafter she was less prominent. She wrote a novel, The call to arms: a tale of the land league (1929) under the pseudonym ‘Esther Graham’ and was a founder member of the Catholic Writers Guild in 1947. She died 31 May 1948 at her home in Churchtown, Dundrum, Co. Dublin, and was buried in Deansgrange cemetery. Her papers, consisting mainly of correspondence during her time in prison, are held in the UCD archives.
Her elder sister, Kathleen O'Brennan (c.1876–1948), playwright and journalist, was an early activist in the Gaelic League, where she met Sinéad de Valera (qv). In 1918/19, she undertook a lecture tour in the USA, speaking on Sinn Féin, the place of women in the Irish republic, and Feis Ceoil. Returning to Ireland, she became involved with the Abbey theatre and wrote a two-act play, ‘Full measure’, which was performed in the Abbey in August 1928, with her friend Sara Allgood (qv) in the lead. Set in a country town, it dealt with emigration and the stranglehold of the gombeen man on rural communities. It enjoyed some popular but little critical success. The Irish Times critic told the inveterate theatregoer Joseph Holloway (qv) that it lacked staying power, but Holloway found it ‘subtle, delicate . . . the character drawing and dialogue were excellent and the play interesting and biting in part’ (Holloway, i, 38). The following year he noted the difficulty of getting a second play put on in the Abbey, citing O'Brennan as an instance of someone whose later work was rejected despite early success. She continued to frequent the Abbey, where she often met Holloway, and may have worked there in some capacity, but she had no more plays performed. In later years she supported herself through journalism, working as one of the few female reporters on the Irish Press, where she was described as peculiar and ‘very mannishly dressed, complete with pince-nez, at one side of which hung a shoe lace for antique style and support’ (Oram, 178). Like Lily, she was diminutive in stature. In 1942 she began to contribute regular articles to the Leader – these were mostly obituaries and appreciations. She particularly championed women whose work she felt was overlooked, such as Louise Gavan Duffy (qv), a headmistress, Lily Williams (1874–1940), an artist, and Agnes O'Farrelly (qv), an academic. She contributed until her death on 12 May 1948, less than three weeks before Lily's death.