Elizabeth was given a place in Vault 51 alongside her husband. Although she supported her husband's initial bid for leadership, his indiscretions and romance with Carmen Greene eventually led her to strike out on her own. An innocuous suggestion from ZAX 1.3c that she should look after her health led to an affair with Matthew Johnston, a personal trainer in the vault.
In August 2078, things came to a head. ZAX engineered a confrontation between them and their lovers, putting the four of them in one room and letting them kill one another: Elizabeth strangled Carmen, Matthew shot Elizabeth, and Joel shot Matthew before dying himself.