Who is Chi/Minh from Catfish and Mandala: A Two-wheeled Voyage Through the Landscape and Memory of Vietnam and what is their importance?

Andrew's older sister, Chi (Minh) underwent a sex change operation when she became an adult. As a girl, she never felt comfortable..... never quite fit in. Her confusion led to conflicts with her father, whose rigid rules of conduct she opposed. Her opposition was responded to with beatings. Andrew had a good relationship with Chi before she ran away to San Francisco. They were reunited 17 years later, after Chi became Minh.