"I am no one, I sin like the whole world," she said, "but I believe they are protecting me, I feel that they and Our Lady protect me."
Recalling memories shared by her father, Marto said Joao had been present with Francisco and Jacinta at the apparition of Mary in Valinhos, which took place in August, "but he didn't see anything."
"It was only Francisco, Jacinta, Lucia and my father, but he said that even though he opened his eyes and looked, he saw nothing," she said.
Around the time Mary was to appear, Jacinta wasn't there at first, she said, explaining that when Lucia asked him to go find her, Joao "didn't want to, because he wanted to see." He eventually went to find Jacinta, and when she arrived Mary appeared, but even though he waited with them, Joao couldn't see anything.
Two months later when the "miracle of the sun" took place Oct. 13, 1917, Marto said her father, who was only 11 at the time, stayed behind that day because rumors were spreading, likely from other children, that "if the miracle of the sun didn't happen the whole family would die."
In order to help the people believe in the authenticity of the apparitions, Lucia had asked Our Lady during the apparition of July 13, 1917, to perform a miracle so people would see that they were true.
However, on that occasion Mary responded by saying that should the children continue to come each month until October, the miracle would occur. So on Oct. 13, the last apparition of Mary to the children, 30-100,000 people gathered to witness the miracle.
News reports and witnesses from the time said the miracle took place when the formerly cloudy sky parted and the sun appeared as an opaque, spinning disk in the sky. Multicolored lights flashed across the landscape and those present before the sun then spun toward earth and then zig-zagged back to its normal position in the sky. Additionally, clothes and mud previously wet from the rain had dried.
But while many members of their family were present for the miracle, Marto said her father "stayed at home (because) he was afraid to die" if the miracle didn't happen, as the rumors had stated.
At just 11 years old, Marto said her father didn't understand everything that was going on, but that after Francisco and Jacinta died, "my father said that he cried a lot, a lot. Because he saw that everything they said was happening."
Speaking of her grandparents, Marto said her grandfather Manuel, father of Francisco and Jacinta, didn't initially understand some of what was happening either, but had always believed his children were telling the truth.
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Jacinta was the first one to tell her parents about seeing Mary after coming home from the first apparition, Marto said, explaining that when people began to say the children had made everything up, her grandfather would respond saying: "My children are not liars. I taught them, so if they say they saw, I think they saw."
After the first appearance Manuel accompanied his children to the following apparitions, and although he didn't see anything, "he said that he heard a sound, like a bee inside a jar."
He was also present for the miracle of the sun, Marto said, explaining that "if he believed before, he continued to believe" after.
Marto said that for her, this belief was extraordinary, because "my grandparents weren't at the beatification, none of it. When their children died they were known, but not with the fame of sanctity."
"So they thought their children were a little different from the others, but they didn't know how it was going to be. It was a question every day," she said, but noted that her grandfather in particular "always believed."
Referring to news of the acceptance of a second miracle allowing for the canonization of her uncle and aunt, Marto said she feels "a big joy" knowing they will be proclaimed saints. The two will be canonized May 13, during Pope Francis' two-day visit to Portugal.