From the back of the card:
Saint Agnes is one of the early martyrs mentioned in the Canon of the Mass. She was only 13 years of age when she was martyred during the reign of Diocletian about the year 304.
Because she was rich and very beautiful, Agnes had many suitors. For all she had the same answer: that she had consecrated her virginity to a heavenly spouse. For this she was accused as a Christian and condemned to death.
Saint Agnes is a most popular saint. Her relics are venerated in Rome in the Basilica that bears her name. She is a special patroness of purity. Her Feast is celebrated on January 21.