Helen is a bit of a drifter and appears to be currently homeless. She is 19 years old and is quite skinny. She has strawberry blonde hair of medium length and a bit of a tan, presumably from hitchhiking.
While staying with Allison, she has admitted to drug use. She explained it sort of mutes the voices she hears. The voices, she says, tell her to do things and point out details to her. This led to her discovering her parents were not human and deciding to end their existence. She ran away to avoid the law, or so she says.
She has demonstrated strength well beyond her appearances, and a high threshold for pain. Frank believes she may be a key in unraveling the mystery of the smoke.