While Pope John XXIII removed her from the Missal, but this did nothing to stop the ever-growing devotion to “the Princess of Paradise.” In fact, her Feast is still kept on August 11th for those attached to the Traditional Catholic Calendar of Saints.
The Cord of St. Philomena and the Medal of St. Philomena are two powerful devotions that are part of our Catholic heritage. These devotions are fully approved by the Church and carry multiple indulgences. For more information, see the website of Catholic Tradition.
An account of her life is quoted on the Traditional Latin Mass Propers website:
Little is known of her life, and the information was received by private revelation from her. Martyred at about age 14 in the early days of the Church.For more information, please consider the book St. Philomena: Powerful With God by Sr. Marie Helene Mohr S.C.
In 1802 the remains of a young woman were found in the catacomb of Saint Priscilla on the Via Salaria. It was covered by stones, the symbols on which indicated that the body was a martyr named Saint Philomena. The bones were exhumed, cataloged, and effectively forgotten since there was so little known about the person.
In 1805 Canon Francis de Lucia of Mugnano, Italy was in the Treasury of the Rare Collection of Christian Antiquity (Treasury of Relics) in the Vatican. When he reached the relics of Saint Philomena he was suddenly struck with a spiritual joy, and requested that he be allowed to enshrine them in a chapel in Mugnano. After some disagreements, settled by the cure of Canon Francis following prayers to Philomena, he was allowed to translate the relics to Mugnano. Miracles began to be reported at the shrine including cures of cancer, healing of wounds, and the Miracle of Mugnano in which Venerable Pauline Jaricot was cured a severe heart ailment overnight. Philomena became the only person recognized as a Saint solely on the basis of miraculous intercession as nothing historical was known of her except her name and the evidence of her martyrdom.
Pope Leo XII granted permission for the erection of altars and churches in her honor. Pope Gregory XVI authorized her public veneration, and named her patroness of the Living Rosary. The cure of Pope Pius IX, while archbishop of Imola, was attributed to Philomena; in 1849, he named her patroness of the Children of Mary. Pope Leo XIII approved the Confraternity of Saint Philomena, and raised it to an Archconfraternity. Pope Pius X raised the Archconfraternity to a Universal Archconfraternity, and named Saint John Vianney its patron. Saint John Vianney himself called Philomena the New Light of the Church Militant, and had a strong and well-known devotion to her. Others with known devotion to her include Saint Anthony Mary Claret, Saint Euphrasia Pelletier, Saint Francis Xavier Cabrini, Saint John Nepomucene Neumann, Saint Madeline Sophie Barat, Saint Peter Chanel, Saint Peter Julian Eymard, Blessed Anna Maria Taigi, and Venerable Pauline Jaricot.
In 1802, the bones of a female between the ages of 13 and 15 were discovered in the catacomb of St. Priscilia. An inscription near her tomb read "Peace be with thee, Philomena", along with drawings of 2 anchors, 3 arrows and a palm. Near her bones was discovered a small glass vial, containing the remains of blood. Because it was a popular custom of the early martyrs to leave symbols and signs such as these, it was easily determined that St. Philomena was a virgin and a martyr. Her popularity soon became widespread, with her most memorable devotees being St. John Vianney, St. Madeleine Sophie Barat, St. Peter Eymard, and St. Peter Chanel. After being miraculously cured, Ven. Pauline Jaricot insisted that Pope Gregory XVI begin an examination for the beatification of St. Philomena, who was to become known as the "wonder worker". After hundreds of other miraculous cures, she was beatified in 1837. St. Philomena, who the pope named as the Patroness of the Living Rosary and the Patroness of the Children of Mary, is the only person recognized as a saint solely on the basis of her powerful intercession, although pertinent revelations regarding her life have been recorded. Her relics are now preserved in Mugnano, Italy.
O God, who among the other marvels of Thy power, hast granted even to the weaker sex the victory of martyrdom, mercifully grant, that we who celebrate the heavenly birthday of blessed Philomena, Thy Virgin and Martyr, may by her example draw nearer to Thee. Through our Lord . . .
Prayer Sources: 1945 Roman Catholic Daily Missal