Vibia Perpetua was a noblewoman in her early twenties with an infant; Felicitas was a pregnant slave. They are the two Christian martyrs of the third century about whom we know the most -- the text that gives their tale, the Passion of Saints Perpetua and Felicity, and the part of detailing St. Perpetua's life up to a bit before her death seems to be genuinely written by Perpetua herself. Perpetua became a Christian catechumen and there was a big blow-up at home, as her father demanded that she recant. She refuses, is baptized, and is arrested. In part because she is a noblewoman and in part because she is nursing an infant, the guards can be bribed and she is moved to a better part of the prison, where she continues to care for the child, and continues to refuse to give up her Christian faith. From an anonymous later editor we learn of a few other Christians who were arrested at the same time: Secundulus dies in prison, Felicitas gives birth in prison, and Revocatus, Saturus, Perpetua, and Felicity are eventually taken to the arena and, after being harried and wounded by wild animals, are slain by the sword.
A story that has always stuck with me as perfectly capturing the gift of fortitude is that when St. Felicity was in difficult labor pains in prison, a guard jeeringly asked her how, if she was complaining now, she would handle being thrown to the beasts, to which she replied, "I now suffer myself what I suffer, but then Another will suffer in me."
And ever since that arena day in the early third century, the noblewoman and the slave girl, mother-martyrs who died together into perpetual happiness, have been remembered together.