Veronica – often identified with the bloody woman from the healing story in the Gospel of Matthew 9:20 – told the messenger of the sick emperor Tiberius- according to the legend spread in the Western church, that in order to always have an image of Jesus Christ with her, whom she could not follow from place to place, she had asked him for an image. She had a cloth with her, handed it to him and got it back with his indented face. Veronica went with the messenger to Rome, the cloth proved its healing power: Tiberius, who had a wasp nest in his head, became healthy.
Around 1300, extended versions of the legend were created, which assign Veronica to the Way of the Cross of Christ: Veronica was therefore one of the many women of whom the Gospel of Luke (23:27) reports, at the Way of the Cross; when the Savior collapsed, she handed him her sweat cloth, on which the imprint of his face with the crown of thorns was preserved.
Joachim Schäfer: Article Veronika, from the Ecumenical Dictionary of Saints – https://www.heiligenlexikon.de/BiographienV/Veronika.htm