Sylvia is a former resident of Limetown. She was one of seventeen children in the town, and the only known child survivor.

Sylvia is first mentioned in the episode "Winona", She is mentioned again in "Cost-Benefit Analysis." In Season 2, Alison mentions that Emile sought to keep Sylvia safe from "Glass Joe" in the events post Limetown.

Sylvia first appears on the podcast in season 2's "Bordeaux". Charley chases her down in France, claiming to be on the behalf of Emile. Sylvia recounts that Lenore kept her alive as a favor to Emile. Post-Limetown, she woke up in Melbourne, Australia, and was given the identity of Morgan Litton.

Two years into boarding school, Emile found Sylvia to tell her that Daniel Rassmueller was killing everyone from Limetown. He and Lenore worked together to protect Sylvia, moving her around Australia under different pseudonyms. She received regular updates via notes about Daniel's whereabouts.