Her parents were Mary Ellen (born Hodding) and a wine merchant named John Nicholas.

She made her first donation to Emily Ayckbowm's Community of the Sisters of the Church when she was four years old.

Her parents were well off and she became a novice in 1892,[1] In 1895 she took the name of Sister Rosalie encouraged by Emily Ayckbowm to use her talent for business organisation.

[2] She and two other sisters, Vera and Susanna, arrived at Fremantle on the ship named Australia on 20 November 1901.

She then went to England where she gained the support of Arthur Winnington-Ingram, the Bishop of London, and the editors of two newspapers.