And I could add Anna Komneme, who was definitely Roman, but not in the Classical period nor the city of Rome. Boudicca and Zenobia were more famous for disagreeing about being Roman, and leading revolts.
Oddly the most famous women of the Roman Empire were commoners in Roman Judea: Mary, Anne, and Mary Magdalene.
Well Irene managed to usurp the throne in a similar way to most male emperors (by scheming and murdering her opponents, even if one of them happened to be her own son…) and even managed to rule on her own right for a while. Which was extremely unique historically, even by modern standards (how many female dictators are there?).
Oddly the most famous women of the Roman Empire were commoners in Roman Judea: Mary, Anne, and Mary Magdalene.