Marinus became accomplished in virtue, and distinguished by humility and obedience. After several years, when her father died, she intensified her ascetical efforts and received from the Lord the gift to heal those afflicted by unclean spirits.
One time the “monk” Marinus was sent with other monks to the monastery gardens, and along the way they had to spend the night at an inn. The inn-keeper’s daughter, having sinned with one of the lodgers, denounced the Marinus and named “him” as the father of her child. The girl’s father complained to the igumen of the monastery, who expelled the “sinful brother.” The saint spoke not a word in her defense and began to live outside the monastery wall. When the hapless girl gave birth to a boy, the inn-keeper brought it to Marinus. Without a word he put his grandson down before her and left. The saint took the infant and began to raise him.
After three years the brethren begged the igumen to take back the “monk” Marinus into the monastery. The igumen, who very reluctantly gave in to their requests, began to assign Marinus very difficult obediences, which she fulfilled with the greatest of zeal, while also raising her foster child.
Three years later the saint peacefully reposed in her cell. The brethren saw the deceased “monk” and the boy crying over “him”. As they began to dress the saint for burial, her secret was revealed. The igumen of the monastery tearfully asked forgiveness of the departed, and the inn-keeper followed his example.
The body of Saint Mary was reverently buried in the monastery. The inn-keeper’s daughter came to the grave of the saint and openly confessed her sin. Immediately, she was freed from the evil spirit which had been tormenting her. The boy whom the saint was raising later became a monk.
The relics of the saint were transferred to Constantinople, and were carried off to Venice in 1113.