Elizabeth is a teacher working at Pembroke Day School for Girls.
One day, the school visited a museum which housed New World shipwrecks, such as The Star. However, among the treasures recovered from The Star's wreckage site was a locket, haunted by the spirit of Fiona Duncan, a woman who had been brutalized during the ship's journey and whose ill-treatment was encouraged by her own teacher, Mistress Aloway.
In retaliation, Fiona became a vengeful spirit and sought to punish any teacher she could find. Having already killed at least two, Fiona placed her locket in the possession of a teacher from Pembroke, causing her spirit to relocate there and one night, attack and attempt to murder the teachers.
Elizabeth was one of the intended victims. When the room became icy cold, Elizabeth and another teacher, Karen, tried to warm it up, only for a hooded figure to appear before Karen and kill her. The hooded figure, or the ghostly form of Fiona then approached Elizabeth, managing to throw Elizabeth into a bookshelf before Sam and Dean Winchester arrived, armed with salt which they used to briefly dispel the ghost.
Ultimately, Sam and Dean were able to undo Fiona's suffering by sending her fiance back through time to protect her, thus negating not only her transformation into a vengeful spirit, but also undoing the deaths of all of Fiona's victims.
It is unknown if Elizabeth remembers the encounter, given that Sam and Dean still do.