She was appointed as an "ambassador," along with Lewis, to the town of Megaton by the team leader. Her duties in this position included acting as a contact between the two settlements and to further survey the surrounding environs. She later returned to Vault 101.
When the Lone Wanderer is trying to escape the vault, the player can see Grandma Taylor dead on the floor of the Vault 101 cafeteria surrounded by radroaches. During Trouble on the Homefront, Officer Taylor tells the Lone Wanderer that he "lost [his] poor wife Agnes" because "her old ticker just couldn't take it anymore", indicating that she had died of a heart attack amidst the chaos.