[5][6] After secondary school, O'Brien attended Queen's University Belfast, where she received a Master of Science degree in management information systems and services.
[7][6] In 2005 O'Brien won the Irish dancing championship titles of Ulster, Ireland, Great Britain and the world.
[8] She then moved to work as a financial analyst on a graduate programme with the management consulting part of Deloitte, from August 2008 to December 2009.
She secured a place at NUI Galway to pursue a Master of Arts degree in journalism from September 2010,[10] graduating with First Class Honours, and winning an award for the highest marks in the broadcasting part of her course.
[16][13] In September 2013, O'Brien married Ronan Glynn, who had a friend on the Riverdance staff; he was Deputy Chief Medical Officer of Ireland from 2018 to 2022.