From her mother, Cornificia Faustina had inherited a great estate located in Pisidia.
Commodus’ sister, Lucilla was not happy living as a quiet, private citizen in Rome and became jealous of her brother and her sister-in-law because of all the attention that they received.
In 182, Lucilla, her daughter Plautia, her nephew-in-marriage and with the help of Quadratus Annianus, his adopted son and Cornificia Faustina had planned to assassinate Commodus and replace him with Lucilla and her second husband, the consul Tiberius Claudius Pompeianus Quintianus, as the new rulers of Rome.
Cornificia Faustina, her brother Quadratus Annianus and his adopted son were involved in Lucilla's plot because the three may have had a dynastic dispute with Commodus.
When the conspiracy was revealed, the emperor ordered the deaths of Quadratus Annianus, his adopted son and Quintianus.
Before 200, Annia Faustina had a posthumous honorific inscription dedicated to her late mother at the estate.