Darla is a rather young woman with a violent streak and a love of "bad boys". She left her home in the Wasteland to become Skinny Malone's gun moll, leading her parents to mistakenly believe that she had been kidnapped and to hire synth detective Nick Valentine to retrieve her. Nick successfully tracked her down to Vault 114 but was caught and kept locked away in the overseer's office. When Skinny Malone confronts Nick Valentine and the Sole Survivor during their escape from the Triggermen's headquarters in Vault 114, he is accompanied by Darla and two other Triggermen. Darla urges violence, while Skinny wants to handle the situation his own way.
Unlikely Valentine - The Sole Survivor and Nick Valentine encounter Skinny Malone and Darla on their way out of Vault 114. She has to be killed on the way out unless the player passes one of two speech checks:
Through a medium-difficulty speech check, the Sole Survivor can convince Darla to leave the scene (either by reminding her that she has parents that care for her, or by telling her to "remember the Quarry and Lilly June on the rocks"), afterwards Malone will give the Survivor and Nick ten seconds to leave the vault before turning hostile.
Through a hard-difficulty check, the Sole Survivor can convince Darla that he/she is a more dominant alpha figure than Skinny, inciting her to attack Skinny on behalf of the Sole Survivor.
If she is convinced to leave Skinny Malone, or to attack Skinny and survives the fight, Darla can sometimes appear traveling the Wasteland in random encounters. When interacting with her she will say several things, such as "Screw Skinny Malone, who needs that big galoot anyway?", and "I'm going home to my parents, screw these low-life gangsters".