"Today is a special day not only for the Sisters but also for Australia and the universal Church," said Anne Derwin, a nun with the Sisters of St Joseph order founded by MacKillop.
"It is a day to acknowledge Mary who is not only truly saintly but also one of Australia's true heroes."
Melbourne-born MacKillop has already passed the first stages to sainthood by being beatified by the previous Pope John Paul II in 1995 after having another miracle attributed to her.
In that case, the Vatican confirmed that prayers to MacKillop had healed a woman with terminal leukaemia, a recovery which could not be explained by science.
MacKillop co-founded the Sisters of St Joseph of the Sacred Heart in 1866 and established schools and charitable institutions uniquely devised to meet the difficulties of the fledging Australian colonies.
"Mary was a woman truly ahead of her time; she was bold and tenacious and let nothing stand in the way of her care for others," Derwin said.
"Her strength, humour and egalitarian vision have important relevance in today's busy and complex times."
Australian Catholics are now awaiting an announcement from the Vatican on the canonisation of MacKillop, a ceremony they hope will take place in Rome in 2010.
"The universal recognition of Mary's holiness for the Church and the whole world will inspire future generations both in Australia and throughout the world," Derwin said.
Pope Benedict XVI made visiting MacKillop's memorial chapel in North Sydney a priority during his stay in Australia for the Catholic Church's World Youth Day celebrations in 2008. He was the third Pope to pray at the tomb.
By the time of her death in 1909, MacKillop led 750 nuns and had 117 schools which taught some 12,400 students. She had also opened orphanages and homes to care for the homeless and destitute.
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