Thư was born in 1922. Thư's father was Thái and her mother was Cửu Nguyễn. Her paternal grandparents were Tại and Yên Nguyễn. She had five brothers and three sisters, named Hy, Hạnh, Tý, Thủy, An, Đỏ, Khuê and Nhậm. She is the third youngest of the nine children.