Uí Choisdeailbh, Eibhlín (Edith Costello) (1870–1962), folksong collector, Irish language enthusiast, and political activist, was born 27 June 1870, probably in the Strand union workhouse, St Pancras, London. She was christened Edith Drury and raised a member of the Church of England. Practically nothing is known of her parents. Some accounts state her father was Michael Drury , a native of Co. Limerick, and her mother Agnes (Hopton Costello) was Welsh, while others claim that her father was Welsh and her mother was from Limerick. Information on her early life and education is negligible but it is likely that a charitable society assisted with her education. She qualified as a teacher and later became principal of St Michael's Church of England school, Buckingham Palace Road, London. She joined the Irish Literary Society in London where she became acquainted with the Yeats sisters. She began collecting songs in Irish from emigrants there and joined the London branch of the Gaelic League (Conradh na Gaeilge) at its inaugural meeting in 1896. During the next six years she played an active role in the organisation, being elected to the committee on 3 November 1898. She was also involved in other Irish-language organisations in London and taught singing classes.
She travelled as a delegate to the Conradh ard fheis in Dublin in 1902, remaining in Ireland afterwards to assist Úna Ní Fhaircheallaigh (Agnes O'Farrelly (qv)) and Dr Mícheál Ó hIceadha (Michael O'Hickey (qv)) in organising an aeraíocht (open air festival) on Inis Meáin. Her first visit to Tuam, Co. Galway, also occurred at this time. Through her involvement in Conradh she presented prizes at Tuam feis. Around this time also she converted to catholicism and thus had to resign her teaching post in London. She changed her name to Eibhlín and moved to Tuam in 1903 to become a teacher in the Presentation convent. There she became acquainted with Sr Fursa who had a wide knowledge of Irish music and was later to assist her in collecting songs in the Irish language.
She was a founder member of Coláiste Connacht in Spiddal, Co. Galway, in 1905 and served as chairman of its committee. She represented the college at a meeting of Irish colleges in Dublin at Easter 1916. During the rising she was in the city centre and believed the meeting had been organised to enable certain representatives to be there for it.
Between 1908 and 1913 she began collecting folksongs from Irish speakers and others in Galway and Mayo while accompanying her husband, Thomas Bodkin Costello (qv), on his medical rounds in the county. Eighty of these were included in vol. xvi of the Irish Folksong Society Journal (1918). She later became vice-president of the Irish Folk Song Society and in 1923 published a collection under the title Amhráin mhuighe seola. This was one of the first publications of Irish songs that included the text and the music as well as translations and notes. It contains such popular songs as ‘Sail óg rua’, ‘Na buachaillí bána’, ‘Thugamar féin an samhradh linn’, ‘An droighneán donn’, ‘Anach chuain’ and ‘Moll dubh an ghleanna’. The most prominent contributor to this work was Maggie Hession from Bailedóite, Belclare, Co. Galway, a strong Irish-speaking area at that time. Uí Choisdeailbh noted in the introduction that she had ‘discovered a rich field of song, practically untouched but in imminent danger of being lost through indifference and neglect’. It is also clear from the introduction that she saw herself as following in the footsteps of Edward Bunting (qv), George Petrie (qv) and Patrick Weston Joyce (qv).
During the war of independence she stood for Sinn Féin in the 1920 local elections and became the first woman district councillor for north Galway. She became a Tuam town commissioner and was subsequently elected chairman; it is reported she never missed a meeting, even during the Black and Tan raids. Her own house was raided because she often hid Volunteers who were on the run. Also in 1921 she was elected to the Tuam board of guardians and became a judge in the Sinn Féin arbitration courts between 1921 and 1922. A supporter of the treaty, in 1923 she joined Cumann na Saoirse, a women's organisation founded the previous March to help the establishment of the new state. During the second world war she organised Red Cross services.
An active campaigner on social issues, particularly women's rights, she was elected as a Cumann na nGaedheal member to the first Free State senate on 7 December 1922. She remained a senator until her defeat in the 1934 election. She was a member of the Seanad committee on Irish manuscripts from 1923 to 1924 and of the select committee to consider the Dublin reconstruction (emergency provisions) bill, 1924. Continuing her role as an Irish-language activist, she sought to have Irish included in official documents in the new state. Together with Jennie Wyse Power (qv) she succeeded in convincing the Seanad to reject the civil service regulation bill, 1925, at second stage and delay its introduction for twelve months. This bill, sponsored by the Cumann na nGaedheal government, had proposed to confine women to the lower grades of the civil service. It was defeated in the Seanad by 20 votes to 9. She was also responsible for forcing the amendment of the juries bill, 1927, which had attempted to exclude Irish women from serving on juries. A compromise was reached whereby women were able to apply to have their names retained on the state's jury rolls. She emerged as anti-divorce during the debate on the Censorship of publications bill, 1928. She supported the illegitimate children (affiliation orders) bill, 1929, which sought to improve the status of unmarried mothers who refused to enter the Magdalen asylums and other homes by giving them the right to seek financial assistance from the father of their child. She supported a proposal, rejected by the government, to raise the age of consent to eighteen in case of indecent or sexual assault, arguing that it would provide greater protection for females.
She married Thomas Bodkin Costello, medical doctor and antiquary, on 28 October 1903 in Tuam cathedral and they had one daughter. On her marriage Uí Choisdeailbh resigned both her teaching job and her Irish dancing class in Tuam.
Uí Choisdeailbh died 14 March 1962 in the Bon Secours Nursing Home, Tuam, and was buried in the New Cemetery, Tuam.