Fadilla was the eighth child of Marcus Aurelius, the heir apparent of the emperor Antoninus Pius, and Faustina, who would give birth to six children more. Even in Antiquity, a family of fourteen girls and boys was very large, and this was recognized: coins were minted to celebrate the fertility (fecunditas) of the empress, and her couples who wanted children sacrificed to her statue in the Temple of Venus and Roma. However, infant mortality was on normal pre-industrial levels in the royal family, and only six children survived their parents. Fadilla, named after a sister of Faustina, was one of them.
When she was two years old, her father succeeded to the throne, which meant that her marriage was to be an important one. Her husband had to be a man of the highest nobility, and might even dream of the imperial purple himself, because all boys in the family appeared to die. Only Commodus remained alive and it was possible that he would die as well. in that case, the husbands of Fadilla and her sisters Lucilla and Annia Faustina would contend for the throne. Fadilla's husband was Marcus Peducaeus Plautius Quintillus, who, as adopted son of Marcus Peducaeus Stloga Priscinus (consul in 141), did indeed belong to the highest nobility. He had the distinction of being consul in 177, together with the emperor himself.
When Marcus Aurelius died in 180, Commodus was still alive, and became the next ruler of the Mediterranean world. He was still young, and Fadilla's husband was one of his main advisers. His sister had some influence as well. According to the Greek author Herodian,note[Herodian, History of the Roman Empire 1.13.1.] she warned his brother that his praetorian prefect, Cleander, was becoming too powerful. Another source, Cassius Dio, says that the warning was given by Commodus' mistress Marcia,note[Cassius Dio, Roman History 73.13.5.] but this may be a mistake, inspired by the fact that Marcia was to play an important role when Commodus himself was becoming too despotical, in 192, and assassinated.
By then, the imperial family had been discredited. Commodus' last years had been a reign of terror. Fadilla's husband was ignored when a successor was chosen: another member of Commodus' board of advisers, Pertinax, assumed the imperial purple. He was murdered after a very brief reign, and a new dynasty was founded by Septimius Severus, who ordered the execution of Marcus Peducaeus Plautius Quintillus in 205. It is not recorded whether Fadilla was still alive.