Mary McKillop, an Australian nun who confronted authorities within the Catholic Church and helped uncover sexual abuse by an Irish Catholic priest, was canonised by Pope Benedict XVI on Sunday. Thousands of Australians poured onto the streets and into churches on Sunday to mark the impending canonisation of a feisty nun who died a century ago as the country’s first Roman Catholic saint.

In her lifetime, Mary MacKillop struggled with the Catholic authorities and was once briefly excommunicated. She was also instrumental in exposing sexual abuse by an Irish Catholic priest.

She was one of six Catholic figures being canonised by Pope Benedict XVI on Sunday at a ceremony in Rome. “It is a great day,” Sister Monica Cavanagh, acting secretary general of MacKillop’s order, said. “We are proud of Mary. We are proud that she’s Australian that she’s a woman and she’s a Josephite. We are just filled with great joy. We have probably even had a few tears today,” Cavanagh said from MacKillop’s tomb, a short distance from Sydney’s famous harbour.

In the town of Penola in South Australia State, where in 1866 MacKillop founded the Sisters of Saint Joseph of the Sacred Heart, a special mass was celebrated with children dressing up in 19^th century costume.