This unnamed woman was the wife of Larry Ganem.
Sometime after destruction of the Men of Letters in 1958, Larry married this woman and the two lived happily for many years. Due to Larry's blindness and increasingly old age, this woman often took care of her husband.
When Knight of Hell Abaddon went in search of Henry Winchester, a Man of Letters who held a valuable object she wished to obtain, she discovered through the memories of a comic book store clerk that Henry was going to visit Larry. In hopes of intercepting Henry, Abaddon took possession of Larry's wife.
As predicted, Larry was paid a visit, but by Henry's grandson Sam Winchester. Abaddon pretended to be Larry's wife and served both men a drink. She listened closely to their conversation. After learning about the Men of Letters bunker, Abaddon revealed herself by knocking Sam out and killing Larry.
She then killed Larry's wife, and vancated her body in favor of her former vessel.