She has also worked as an international election monitor for the OSCE, a human rights observer in Israel and Palestine, and as chairperson of the Irish Blood Transfusion Service and a director of other public bodies.
A keen sailor during her school years, she began a career in sailing instruction in Morocco, but then returned to Dublin and with family help joined a firm of accountants there.
Engaged by 1972, they settled in Manchester in the mid-1970s, and she both worked in her own practice and with Peat Marwick Mitchell, one of the main firms which merged into KPMG[5] as well as beginning her academic career lecturing there.
[4] Barker has also worked as a visiting professor in universities in Europe (Angers), Africa (Dar es Salaam, Cape Town, Malawi), North America (New York, Boston) and Australia (Sydney), and extensively as an external examiner.
[5] Barker completed an MPhil in Gender Studies at her alma mater, Trinity College Dublin, and later took her PhD with a thesis on the sharing of financial data with employees,[7] the first doctorate in accounting in Ireland.
[7] Barker volunteered with the Organization for Security and Co-operation in Europe in oversight of elections, including in South Africa, Bosnia-Herzegovina, Kazakhstan, Montenegro, Malawi and Belarus.
[5] Barker has worked with the Dublin Rape Crisis Centre since its foundation in 1979,[25] including as a volunteer counsellor, and served on the board of Women's Aid.
[32] She was one of two keynote speakers at a special Dublin and Glendalough Diocesan Forum hosted by the Archbishop at All Hallows College in 2001,[33] and was elected a delegate member of the General Synod of the Church of Ireland for 2020 to 2023.