THOUSANDS of Australians are set to mark the centenary of Mother Mary MacKillop's death today.The Sisters of St Joseph are preparing for a public day of nationwide reflection and thanksgiving, 100 years after their founder's death. Sister Maria Casey, who has spent more than a year in Rome leading the campaign for MacKillop's canonisation, said the anniversary was a time to reflect on her selfless life.MacKillop began her teaching career at Portland in 1862 before setting up a schoolhouse in Penola, South Australia, in 1866.She was joined there by other Catholic nuns who became known as the Sisters of St Joseph. She then spent her life educating children in remote areas and helping the needy, including ex-prisoners and former prostitutes. School children, priests, nuns, Catholic congregation members and secular humanitarians alike will join together this weekend to remember her life and work. "This is where it all began," said Claire Larkin, chairwoman for the management committee of the Mary MacKillop Penola Centre. "Penola has a very special place in her story." The town is planning a full mass and religious art exhibition opening for the celebrations.Almost since Mackillop's death in 1909, there has been a push to make her Australia's first saint. The final processes of her canonisation are under way in Rome. To be named a saint her second miracle - healing a woman with inoperable cancer during the mid-1890s - must be proved. The Vatican has recognised her first miracle - healing a woman of terminal leukaemia. Sister Casey said an announcement today to coincide with the anniversary was unlikely. "We won't rule out another miracle but I wouldn't be expecting it," she said.She said one of the things that was so important about the celebrations was the recognition that Mackillop's legacy was still alive 100 years after her death. "I think tomorrow is (to) stop and celebrate that this woman is still living in our midst, we are the living ambassadors of that lady now," Sister Casey said yesterday."Her work is going on through so many people and she's touching their lives so much." About 8000 people are expected to gather at North Sydney Oval to see a live broadcast of the invitation-only Catholic mass led by Cardinal George Pell at St Mary's Church. with AAP