Lilly was discovered on the streets of Kelowna, British Columbia, by Ford modeling agency. Although she initially decided to pass on a modeling career, she went ahead and signed with Ford anyway, to help pay for her University of British Columbia tuition and expenses. Despite being signed to Ford Models, she was never actually a fashion model, working instead with their acting branch.

She was previously featured in several provocative television commercials for LiveLinks Chatline, a service billed as the "best place to meet local singles for dating, friendship, or phone chat." Her image is still used to promote the service. She also appeared on G4's Judgment Day. She appeared uncredited in the 2003 film Freddy vs. Jason as a high-school girl leaning against a locker, and in an episode of Smallville in a pool hall scene. She also had a guest appearance on the ABC supernatural horror series Kingdom Hospital (2004). Lilly's first speaking role was on Lost. She also appeared in th