This brave Saint was only 12 when she died for the faith.
“St. Agnes (c. 304) like St. Cecilia, is to be numbered among the most famous martyrs of Rome. When the Diocletian persecution was at its height, and when priests as well as laymen were apostatizing from the faith, Agnes, a girl of twelve, freely chose to die for Christ. When she was commanded to offer incense to false gods, she raised her hand to Christ and made the Sign of the Cross. When the heathens threatened to bind her hand and foot, she herself hastened to the place of torture as a bride to her wedding feast. Pain had no terror for her—although the fetters slipped from her small hands while even the pagan bystanders were moved to tears.
When the son of the Roman prefect offered to marry her, she replied: “The one to whom I am betrothed is Christ Whom the angels serve.” When the executioner, who was to behead her, hesitated, she encouraged him with the words: “Strike, without fear, for the bride does her Spouse an injury if she makes Him wait”. The name of “Agnes” means “lamb-life,” and hence the lamb is the symbol of the modesty and innocence of the virgin-martyr.” Read more at Catholic Culture.
Mike Aquilina over at The Way of the Fathers, notes that:
Today’s saint, Agnes of Rome, is long overdue for a revival. Why? She was probably the most revered female martyr of the early Church — outstanding in a field that included Blandina and Perpetua, among others. St. Jerome was not a man easily impressed, but of today’s saint, his near-contemporary, he wrote: “Every people, whatever their tongue, praise the name of Saint Agnes.” Prudentius wrote a long poem and a hymn in her honor. Ambrose extolled her as the model virgin. Augustine praised her. Damasus memorialized her in verse. Her name means lamb, and in art she often appears holding a lamb. Read more here.
The awesome Fr. Z , What Does the Prayer really say? has some fascinating information. Get thou there!