She lived when Christians were more solicitous to live well than to write much: they knew how to die for Christ, but did not compile long books in which vanity has often a greater share than charity. Hence no particular account of her actions has been handed down to us. But how eminent her sanctity was we may judge from the lustre by which it was distinguished among apostles, prophets, and martyrs. She is said to have been a daughter of the apostle St. Peter; that St. Peter was married before his vocation to the apostleship we learn from the Gospel. St. Clement of Alexandria assures us that his wife attained to the glory of martyrdom, at which Peter himself encouraged her, bidding her to remember Our Lord. But it seems not certain whether St. Petronilla was more than the spiritual daughter of that apostle. She flourished at Rome, and was buried on the way to Ardea, where in ancient times a cemetery and a church bore her name.
Feast Day of Saint Petronilla
The Feast Day of Saint Petronilla is May 31. The origin of Feast Days: most saints have specially designated feast days and are associated with a specific day of the year and these are referred to as the saint's feast day. The feast days first arose from the very early Christian custom of the annual commemoration of martyrs on the dates of their deaths at the same time celebrating their birth into heaven.