Leila is a Roman demigod daughter of Ceres, centurion of the Fourth Cohort and an old comrade of Jason Grace. She fought in the Second Demigod Civil War, led by Octavian, centurion of the First Cohort, and reluctantly by Praetor Reyna Avila Ramírez-Arellano.
Little is known about Leila's past. It can be inferred that she was trained at the Wolf House by the wolf goddess Lupa. At some point, she made her way south toward Camp Jupiter and was accepted into the legion by the augur.
It is unknown how long Leila has been a member of Camp Jupiter or even if she took part in the Titan War. However when Jason Grace sees her in a vision, he refers to her as an old comrade. It is also unknown if she fought in the Attack on Camp Jupiter, alongside Reyna Avila Ramírez-Arellano and the new recruit Percy Jackson, as she is never mentioned by name.
Reyna describes Leila as "quite levelheaded". She isn't known to be aggressive.
After confronting the pirate Sciron, Jason fell into unconscious mid-air, dreaming about the Romans' gathering in New York before their planned attack on Camp Half-Blood. Jason recognized Leila among his old comrades, which also included Dakota, Nathan, and Marcus.
Leila was present when Rachel Dare arrived with Grover Underwood, as ambassadors from Camp Half-Blood. Rachel provided Reyna with a message from Annabeth Chase. Upon this, Reyna departed for Greece, reluctantly leaving Octavian in charge. As soon as Reyna was out of earshot, Octavian told Leila and the others that there were going to be some changes in the legion's plans.
Leila arrives with Dakota and Mike Kahale to arrest Reyna and Nico for treason. But before they can Octavian arrives to see what was taking so long. But it is really Tyson and Ella who knock out the son of Venus and were about to knock out the other two when they stated their loyalty to Reyna. She went with Dakota and Nico to the front with an unconscious Kahale. They were driven by Jules-Albert to the Roman base camp where she and Dakota tried to get there cohorts to back Reyna. Before they can the Greeks are discovered trying to rige the ongoaers. After Reyna returns the Athena Parthinon and Gaia awakes she along with the her, the second, and third cohorts are traped waist deep in the earth with some of the monsters. The Fifth and First cohorts along with the Greeks come to their aid.
- Chlorokinesis: As the daughter of Ceres, she has absolute control over plants.
- Leila is a variant of the Arabic name meaning "night."