Sheila graduated from the School of Architecture University College Dublin in 1976 and worked in London for Spence and Webster, Colqhoun and Miller and Stirling Wilford Associates.  Through her work for Stirling Wilford on the design and detailed development of the Tate’s Clore Gallery at Millbank, she gained valuable experience in design of specialist galleries, conservation workshops and public facilities.   

Sheila also has a master’s degree in Environmental Design from the Royal College of Art in London. She has developed her expertise in the area of environmental design through her research and teaching role at the School of Architecture U.C.D.

She was a member of the Interim Board of the National Museum with the specific task of advising on the appropriate strategy for the development of the Collins Barracks complex as a permanent home for the Museum. She is an external examiner at Cambridge University School of Architecture, and the Architectural Association, London.

In 1988 she set up O'Donnell + Tuomey with John Tuomey and in 1994 was raised to the rank of Fellow by the RIAI in recognition of her contribution to Irish Architecture practice

She was a director of Group 91 Architects, who in 1991 won the urban design competition for the Architectural Framework for Temple Bar. Group 91 were consultants to Temple Bar Properties on their Development Programme 1992-97.

She was partner in charge for the Irish Film Centre (completed 1992), Blackwood Golf Centre (1994), UCC Good Shepherd campus (1995-98), St. Angela’s College (ongoing), Connemara West Centre crèche (ongoing), Barnardos childcare building (ongoing) and Stanhope Street School Feasibility Study (2000 - 2003).

She worked with John Tuomey on the briefing and design stages of the Glucksman Gallery and is currently managing the contract for Cherry Orchard School, and overseeing design development of a social housing scheme in Dublin’s Liberties.

She has taken the RIAI block course in conservation, leading to accreditation in Conservation at Grade 3.