Louise-Mary O'Brien was born into a large family in Midleton, Ireland, on 16 August 1905. She felt her first call to evangelisation at a Sunday Mass in Ballycotton. Louise-Mary also studied as a boarder with the Sisters of Saint Clotilde in Eltham Park.

On 31 May 1924, Louise-Mary entered the novitiate of the Sisters of Saint Clotilde in Paris and become Sister Veronica. On 8 December 1935, with the agreement of her superiors, she left the congregation of Saint Clotilde to begin life as a lay missionary. After meeting Frank Duff in London she joined the Legion of Mary.

In 1939, Veronica arrived in Nevers. With the help of Bishop Flynn and his priests, she founded the Legion of Mary in France. After the war, she moved to Paris, from where she brought the Legion of Mary to other European countries.

In 1948, Veronica had a decisive meeting with Bishop Léon-Joseph Suenens. This marked the beginning of a collaboration that would last until the end of her life.

In 1958, Veronica moved to Brussels. She became the spiritual adviser to King Baudouin. She encouraged the Church to welcome the Charismatic Renewal, among other things through the 1975 world pilgrimage to Rome and the theological study of the Malines documents. Together with Cardinal Suenens, she founded the FIAT association.

The example of this complementarity, seen at various levels in the difference between ‘institution’ and “charisms”, could help to clarify and nuance the ongoing debates on the place of women in the Church – to value them ‘more, but differently’.

During a spiritual experience she received the FIAT rosary. She died on 19 February 1998 at the age of 92.