She was best known for her performances as Misty, Jessie, and Jigglypuff in the first eight seasons of the English dub of the TV series Pokémon.

[6] Lillis became known for voicing Misty and Jessie in the English dub of the Pokémon anime.

According to Veronica Taylor, Lillis had difficulty finding work during the COVID-19 pandemic, in part due to a lack of recording equipment at her home.

[9] The campaign raised $98,000 by the time she died, with the money going towards Lillis's remaining bills, a memorial service and cancer research.

[5] The cancer spread to her spine, which left her barely able to walk, and she eventually moved into a Los Angeles nursing home to receive care.