She became a national school teacher until she went to University College Cork in the 1930s, studying archaeology under Professor Seán P. Ó. Ríordáin.

She met her future husband, Michael J. O'Kelly, known to family as Brian, while in college, and together they were involved in work on many of Ireland's historical sites, and on the setting up of the Cork Public Museum in 1945.

O'Kelly wrote several books for public understanding on the history and importance of Irish sites, and her content is used for the website of Newgrange, for example, even today.

Her significance in archaeology and history was recognised when she was elected a Fellow of the Society of Antiquaries of London in 1984.

She was friends with Gabriel Hayes, the wife of O'Kelly's university tutor Seán P. Ó. Ríordáin, who used her hands as the models for the stations of the cross in Galway cathedral.