Thiện was born in 1920. Thiện's father was Tòng and her mother was Trương Trịnh Thục. Her paternal grandparents were Vinh and Tĩnh Nguyễn Huy. She had four brothers and a sister, named Khải, Phác, Mô, Nam and Quỳnh. She is the second youngest of the six children. She has a half-sister named Nhỏ.