"All I had left was prayer," Mrs Evans told Australia in January when she went public with her story.
Ms Barnett said the Evans' family home in Windale was always flooded with friends there to support her.
"I was just thinking about her then, I don't think anyone dying of cancer would have had so many people in their house every day," she said.
The Evans family moved to Lightning Ridge and travelled around the state to maintain their anonymity while the Vatican considered Mrs Evans' case as a miracle.
Another Australian woman will also be watching the canonisation ceremony with more interest than most.
She is the second woman who was near death when she suddenly recovered from terminal leukaemia, a recovery the Vatican also attributed to Mary MacKillop.
It has been 49 years since the woman prayed for Mary MacKillop's intercession and returned to good health but she has never let her identity be known.
Hers was the first miracle that allowed MacKillop to be beatified in 1995 but the Vatican needed the second miracle which Mrs Evans received, to make her a saint.
"Certainly [she is alive], she has subsequently had a family. She has always been very cautious of her privacy," said Father Brian Lucas, who is general-secretary of the Australian Bishop's Conference.
"There is not much you can say. It was a woman who was terminally ill with leukaemia, very close to death and there was a very sudden cure."
A mother of six, the woman gave birth to a boy in the early 1960s soon after her recovery.
Mary MacKillop's Sisters of Saint Joseph have detailed the arduous process of proving the MacKillop miracles.
Two specialist doctors first examine the nominated person's case to determine if the recovery "can be explained by scientific means". In Mrs Evans case and that of the leukaemia sufferer, there was no medical intervention or treatment. The Vatican requires X-rays, tests and a patient's medical history.
It is then determined if the "cure is outside the normal medical process" and "if there is evidence that surgery or medicine did not bring about the cure".
The cure must also be "complete and permanent".
Miracles must then undergo a theological study to determine the role of prayer.
The Pope will only receive the cases after they have been pored over by cardinals.
There are a host of unofficial miracles the Sisters of Saint Joseph call "favours".
They include Sophie Delezio's remarkable recovery from two horrendous car accidents and Irish man David Keohane who woke from a coma after being bashed in Sydney
