One day Lillian robbed a stagecoach. As she escaped those pursuing her, she came across the Fourth Doctor and Leela, who were looking for a circus. She offered to take them to see the Wolf-People, who were a group of people living with wolves.
When Lillian thought one of the wolves was attacking the Doctor, she tried to shoot it but her gun exploded in her hand, injuring her. The Doctor convinced the Wolf-People to let her stay while she recovered. He left her some medicine, as he and Leela had to leave. Before he left, he told Lillian that the Wolf-People were dying out.
Several months later, Lillian had recovered enough to search for her horse, left behind the day of the stagecoach robbery. However, he was long gone.
Several years later, she helped as one of the women, and her wolf as well, gave birth. Lillian gave both newborns what was left of her medicine.
Decades later, all that was left of the tribe were the wolf-cub and the girl, both of whom Lillian named Erin. The Doctor came back to take her and the Erins away, as they should not have existed. It was the medicine that had allowed them to survive, and had allowed Lillian to live over a hundred years while only appearing to be in her forties. The Doctor took them to the Time Vortex along with others he had taken out of their times. (PROSE: The Bushranger's Story)