She was a great-granddaughter of William Quinn, a native of Tyrone who settled in Tuam to build St. Mary's Cathedral.

[4] After spending eighteen months in a sanatorium, her condition unchanged, she decided to become active in the Legion of Mary, which she joined in Dublin at age 20.

In 1936, at age 29 and dying of tuberculosis, Quinn became a Legion of Mary Envoy, a very active missionary to East and Central Africa,[5] departing in December 1936 for Mombasa.

[4] Fighting her illness, in seven and a half years she established hundreds of Legion branches and councils in today's Tanzania, Kenya, Uganda,[6] Malawi, and Mauritius.

[5] She was declared venerable by Pope John Paul II on 15 December 1994, since when the campaign for her beatification has continued.