This unnamed nurse worked for the Styne Family.
This nurse presumably worked full-time for the Styne Family though its unknown if she was part of the family as well, or an employee.
She was at the Styne Estate when Dean Winchester arrived, prepared to take them out but instead got knocked out and taken to the operating room, where he was greeted by Monroe Frankenstein. Monroe had been prepared for Dean's arrival and planned to harvest Dean's organs with the help of the nurse and Eli Frankenstein. However, the procedure was disrupted by Dean breaking free of his bounds and killing Eli. During the struggle, the nurse grabbled a lethal injection only to be overpowered by Dean who injected her with her own syringe.