Ellie was a ranch hand on the Cassity estate.
When Eliie was young, her mother took a job at the Cassity ranch after her divorce. Her mother started working there before the Cassitys struck oil on their land and became rich. Ellie's lived on the land ever since and now manages it for Alice Cassity and her husband, Carl Granville.
As Dean enters the barn in search of a hellhound, he discovers Ellie drinking and dancing alone in her room. She tries to seduce him but he stops her and warns her to stay in and protect herself; there is something evil outside. She reveals that she knows, and that the evil is coming for her.
After a big dinner on the ranch years ago, she saw Margie kissing Crowley and ran. He found her and sweet-talked her, and asked what her one wish was. She is adamant that he did not force her to sign over her soul; she did it because her mom had Parkinson's disease and she wanted to save her. Dean chastises her, but she retorts: what would he do for his mom? This makes him pause, but then he tells her she had to know this day was coming. She tells him that knew she wasn't going to Heaven, but that Crowley never mentioned any deadline or any monsters. Dean mutters that Crowley probably didn't tell Carl or Margot the details either. Ellie did not know that Margie had made a deal. She says that Carl got drunk a while back and confessed that he had summoned a demon and did "some kind of magic". When he was killed, not knowing about Margie, she surmised that she was next. So, tonight, she just wanted a good meal, some good tunes, and well, Dean.
Sam manages to kill the circling hellhound, giving Ellie a reprieve. Dean tells her she'll need to keep on the move, using hex bags to keep Crowley at bay.