Plutarch describes her as a beautiful woman of good character, well read and a skilled player of the lyre. She was also very well educated in geometry and philosophy.
Cornelia was first married to Publius Licinius Crassus, son of Marcus Licinius Crassus, in 55 or 54 BC, when he returned to Rome after serving under Julius Caesar in Gaul. After her first husband's death at the Battle of Carrhae, Cornelia became the fifth wife of Pompey in 52 BC. She was a faithful follower of Pompey and met him in Mytilene with his son Sextus Pompeius, after the battle of Pharsalus in 48 BC. Together, they fled to Egypt where Pompey was murdered. On his arrival, Caesar punished the murderers of Pompey and gave Cornelia his ashes and signet ring. She returned to Rome and spent the rest of her life in Pompey's estates in Italy.