Saint Aloysius Gonzaga was born on March 9, 1568 to wealthy parents in Italy. His mother wanted him to be a priest, but his father wanted him to become a soldier. When he was only five years old, he was sent to military camp. His mother was very upset when he came home using the bad language he had learned at the camp.
When he was only seven, God touched his heart and Aloysius experienced a sudden understanding of the Faith. He had always said his prayers from the time he was a baby, but now he began to recite Psalms, the Office of Our Lady, and other devotions. He knew from that time that he wanted to become a saint and he lived his life according to that desire. He eventually gave away his inheritance and entered the Society of Jesus (the Jesuits). Aloysius prayed long hours at night and fasted several times a week. When caring for the sick during a plague, he contracted a disease and died at the young age of 23.
*Psalm 1, 3, 4, 8, 15, 19, 23, 27, 34, 51, 62, 95, 103, 121, 139, and 148 (among others) may all be good reading choices for your young saints.