Women, in contrast, were given only one name — either the feminine nomen of the clan for patricians or the feminine cognomen of the family for plebeians. Hence all the daughters of the Julii were called ‘Julia’, or of the Livii ‘Livia’. Sisters were not differentiated. The two daughters of Mark Antony were both called ‘Antonia’. One became the mother of Germanicus, the other the grandmother of Nero. All the daughters of Marius were called ‘Maria’.
— Europe, a History by Norman Davies