Olivia Mary Taaffe was born on June 24, 1832 at Annagh, Co. Galway. Both parents were from well-known families in Galway and had considerable influence over the county, but Olivia’s mother died after giving birth to her, and her father, a somewhat eccentric character left her in the care of her grandparents. Over the years Olivia often complained about the too rigid discipline her grandparents exercised. Fervid protestations of innocence did not save her from punishment for alleged faults and towards the close of her life she was heard to say,
"I never could understand it. How could it possibly have come into their minds that I had told a lie, or that I ever could have been capable of telling a lie?"
But whatever may be thought about the stern discipline of her education, there can be no question that Olivia was brought up in a deeply religious atmosphere.
After a few years, the family moved to a house in Eblana Terrace (now the Parochial House) in Dun Laoghaire. Olivia continued her education here, though was never sent to school, instead being taught by efficient governesses – chiefly French. This association in early life with everything French may explain certain developments and pre-dilections in the later life of Olivia Taaffe.
In August 1855, she was in Paris, and from there wrote a long letter to her sister in French. This letter, which has been preserved; gives a good indication of her outlook on life at the age of twenty-three. Paris was just then entering on the splendours of the Second Empire. In grandeur of buildings and brilliance of fashions, Paris afforded many contrasts with Dublin. The letter, however, is concerned entirely with descriptions of religious ceremonies and devotions. What made the deepest impression on her were the Eucharistic devotions (Daily Benedictions and Perpetual Adorations) and the funeral services. A certain fear of death, founded on a vivid sense of God’s sanctity, always remained with Olivia Taaffe.
In 1862 her sister, Harriet, entered the Presentation Convent at Midleton, Co. Cork.
Olivia was present at the reception. Though her strong faith and ardent love of God, forced her to confess that Harriet "had chosen the better part" still she felt no inclination to follow her example. She never had any doubts about the will of God in her case. "Nun I am not", she would remark, "and nun I will never be".