Ani Pachen assumed her role as chieftainess of the Lemdha clan of Gonjo, when her father died in 1958. In 1959, she rode at the head of their 600 Resistance fighters into the nearby hills to fight against the invader.

After the defeat in war, she was imprisoned for 21 years in notorious Chinese prisons. After her release from prison in January 1981, Pachen went on a pilgrimage. She visited the monasteries of Sera, Drepung, and Ganden, which had all been destroyed in the Cultural Revolution.

She returned to Lhasa to continue support for the cause of Tibetan independence after that. She advertised and participated in three notable demonstrations before fleeing to India ; the September 27 and October 1 demonstrations of 1987 and the March 5 demonstration of 1988.