She's referencing Harold, from the Classic fallout games. In 1 and 2 he was a ghoul with a plant growing out of his head, who eventually became the leader of a community. In fallout 3, he became a tree with the cult. They have similar stories with how the cult misunderstands them, though Harold wants you to kill him against the cult's wishes.its more so supposed to be a reference to a npc in either 3 or new vegas that was basically a person mutated into a tree that had cult followers but didnt want them cant remember the specifics of what the cult wanted thought