At the age of twelve Mary the Egyptian ran away from her parents to the city of Alexandria. Here she lived an extremely dissolute life, causing scandal around her. After 17 years of this life, it took her fancy, in mockery, to accompany a group of pilgrims to Jerusalem, where they were going to celebrate the Exaltation of the Holy Cross.
Once there, Mary tried to enter the Church of the Holy Sepulcher for the celebration, out of curiosity, but she was barred from doing so by an unseen force. She realized that she could not enter God’s house because her impurity.
There was an image of the Blessed Virgin under the porch of the church. Prostrating herself before the Virgin, the young sinner prayed: "O Mother of God, have mercy on the wretch I am! Refuge of Sinners, do not deny me the consolation of seeing and worshiping the sacred wood on which your Son, my Savior, has shed his blood to redeem me. I promise you to go do penance for my crimes wherever you want."
The sinner was then able to enter and prostrate herself before the Holy Cross. Asking the Blessed Virgin, "Where do you want me to go now?" A voice answered, "If you cross the Jordan, you will find glorious rest."
Mary of Egypt confessed her sins, received Holy Communion, and retired to the desert beyond the Jordan. She lived there for 47 years. A priest, Saint Zozimas, brought her communion every year on the same date. When she died, he found her body surrounded by light, and these words written on the sand next to her: "Bury the body of the poor sinner Mary here, and pray for the repose of her soul."
In The Life of the Desert Fathers vol.1
Quoted in Le Rosaire des enfants (The Children's Rosary)