Pope Benedict XVI prayed at her tomb during his visit to Sydney for World Youth Day 2008 and in December 2009 approved the Catholic Church's recognition of a second miracle attributed to her intercession.

[7] MacKillop's parents lived in Roybridge (Scottish Gaelic: Drochaid Ruaidh), Lochaber, Inverness-shire, Scotland, prior to emigrating to Australia.

MacKillop visited the village in the 1870s where St Margaret's, the local parish church of the Roman Catholic Diocese of Argyll and the Isles, now has a shrine to her.

Her younger siblings were Margaret ("Maggie", 1843–1872), John (1845–1867), Annie (1848–1929), Alexandrina ("Lexie", 1850–1882), Donald (1853–1925), Alick (who died at 11 months old) and Peter (1857–1878).

In February 1851, Alexander MacKillop left his family behind after having mortgaged the farm and their livelihood and made a trip to Scotland lasting some 17 months.

This brought her into contact with Fr Julian Tenison-Woods, who had been the parish priest in the south east since his ordination to the priesthood in 1857 after completing his studies at Sevenhill.

The small group began to call themselves the Sisters of St Joseph of the Sacred Heart[6] and moved to a new house in Grote Street, Adelaide.

[17] In an attempt to provide education to all the poor, particularly in rural areas, a school was opened in Yankalilla, South Australia, in October 1867.

MacKillop and her Josephites were also involved with an orphanage; neglected children; girls in danger; the aged poor; a reformatory (in Johnstown near Kapunda); and a home for the aged and incurably ill.[18] Generally, the Josephite sisters were prepared to follow farmers, railway workers and miners into the isolated outback and live as they lived.

[16] They were based at Kangaroo Point and took the ferry or rowed across the Brisbane River to attend Mass at St Stephen's Cathedral.

The Josephite congregation expanded rapidly and, by 1871, 130 sisters were working in more than 40 schools and charitable institutions across South Australia and Queensland.

Despite protests by the laity, Quinn was determined and MacKillop and her Josephite sisters had left the diocese by mid-1880 with other Catholic orders taking over the operation of their schools.

[19] In 1881, Elzear Torreggiani, then Bishop of Armidale and a Capuchin who had worked in both North Wales at Pantasaph and London at Peckham, prior to being consecrated in London in 1879, for the Armidale Diocese; established Mother Mary MacKillop's Sisters of St Joseph at Tenterfield and defended their power of central government at the 1885[20] Plenary Council.

[21] During the time Torreggiani was Bishop of Armidale the Sisters of St Joseph established foundations at Tenterfield (1880), Inverell (1880), Narrabri (1882), Glen Innes (1883), Uralla (1886), Quirindi (1888), Hillgrove (1889), Tingha (1890), Bingara (1902), Walgett (1902), Warialda (1904) and Manilla (1904).

[23] Bishop Sheil spent less than two years of his episcopate in Adelaide and his absences and poor health left the diocese effectively without clear leadership for much of his tenure.

[27] Gardiner explained that after hearing disturbing stories of alleged child abuse involving Fr Keating of the Kapunda parish in South Australia, MacKillop and other nuns spoke to Father Woods, who in turn approached the Vicar General in Adelaide.

One of Keating's fellow priests, Father Charles Horan OFM, was so angered by what Woods and the Josephites had exposed, he swore vengeance on them.

[17] In fact, it was widely known that she drank alcohol on doctor's orders to relieve the symptoms of dysmenorrhea, which often led to her being bedridden for days at a time.

[28] Forbidden to have contact with anyone in the church, MacKillop was given the rent-free use of two houses in Flinders Street, Adelaide by prominent Jewish merchant Emanuel Solomon[32] and was also sheltered by Jesuit priests.

After the acquisition of the Mother House in Kensington in 1872, MacKillop made preparations to leave for Rome to have the "Rule of Life" of the Sisters of St Joseph officially approved.

MacKillop travelled to Rome in 1873 to seek papal approval for the religious congregation and was encouraged in her work by Pope Pius IX.

[18] When MacKillop returned to Australia in January 1875, after an absence of nearly two years, she brought approval from Rome for her sisters and the work they did, materials for her school, books for the convent library, several priests and most of all, 15 new Josephites from Ireland.

With the help from Benson, Barr Smith, the Baker family, Emanuel Solomon and other non-Catholics, the Josephites, with MacKillop as their leader and superior general, were able to continue the religious and other good works, including visiting prisoners in jail.

In South Australia, they had schools in many country towns including, Willunga, Willochra, Yarcowie, Mintaro, Auburn, Jamestown, Laura, Sevenhill, Quorn, Spalding, Georgetown, Robe, Pekina, Appila and several others.

By 1896, MacKillop was back in South Australia, visiting fellow sisters in Port Augusta, Burra, Pekina, Kapunda, Jamestown and Gladstone.

"On January 16th, 1897, the founder of the Sisters of St Joseph of the Sacred Heart, Mother Mary of the Cross,[28] arrived in Petersburg to take over the school.

As a result, her remains were exhumed and transferred on 27 January 1914 to a vault before the altar of the Virgin Mary in the newly built memorial chapel in Mount Street, North Sydney.

[45] On 19 December 2009, the Congregation for the Causes of Saints issued a papal decree formally recognising a second miracle, the complete and permanent cure of Kathleen Evans[46] of inoperable lung and secondary brain cancer in the 1990s.

[49] In the week leading up to her canonisation, the Australian federal government announced that it was protecting the use of MacKillop's name for commercial purposes.

[60] In 2009 Nicholas Buc was commissioned by the Shire of Glenelg to write an hour-long cantata mass for the centenary of the death of MacKillop.