Grandma Goldy was a popular self-proclaimed psychic who resided in Lily Dale.
Goldy was one of a handful of individuals who became popular for their ability to "read" clients and predict the future. Like other successful psychics, Goldy did not possess actual psychic abilities although she personally believed in magic and spells.
As part of her performance, Goldy often relied on crystals and smoke. Because her granddaughter did not share nor did she believe in magic or mysticism, Goldy and Melanie did not get along. Regardless, Melanie was another famous psychic in town, who relied on body language to "read" people.
However, the town's real psychic, Jimmy Tomorrow, became jealous. Despite his natural talent, his lack of showmanship did not grant him the same amount of recognition or fame. He retaliated by commanding the ghost of Margaret Fox to kill these so-called psychics.
Following the death of Imelda Graven, Imelda's necklace fell into the possession of Goldy. Prior to her own death, Goldy had a vision of impending death through unknown means and reported it to her skeptical granddaughter. Goldy was killed, and her necklace disappeared. Sam and Dean Winchester were also drawn to the town as a result of Goldy's death.
Noticing the necklace shared between Imelda and Goldy, the brothers assumed it was a cursed object, but realized it was an ordinary and fake necklace. When Nikolai Lishin also ended up dead after apparently having a vision prior to the incident, Melanie informed Sam and Dean of the similarities. When both Goldy and Nikolai reported experiencing a temperature drop, the brothers realized it was a ghost attack.
Eventually, it was Sam who avenged Goldy and saved Melanie, by killing Jimmy and disposing of Margaret's bones.