This unnamed woman was the mother of Suzie.
While cooking dinner, she orders her daughter to the basement to do the laundry. She rebuffs Suzie's complaint that despite being a girl, she is always given the tough chores.
However, Suzie discovers the Werther Box while down there, and accidentally activates it. The Box's defense mechanisms drives everyone but Suzie to become suicidal. An unconscious Suzie wakes up and rushes upstairs. She enters her father's office to ask where her mother is.
Instead of finding her father, she finds his corpse on the floor, on a puddle of blood next to a recently used handgun. Suzie runs back out into the hall only to find her brother, Brad, hanging himself. Suzie then runs into the kitchen and clutches her mother around the waist, terrified.
Seemingly in a trance, Suzie's mother repeats to her that everything is going to be okay, and promptly slits her own throat. The death of Suzie's mother and the rest of her family permanently traumatizes Suzie.
When the Werther Box is opened again, years later, Suzie begins hallucinating and sees her entire family, each one pale with injuries caused by the respective suicides. Suzie's mother in particular, after expressing anger towards Suzie, reassures her that she doesn't have to be alone anymore. These words drive a terrified Suzie to commit suicide.