Thảo was born in 1899. Thảo's father was Mạnh Cung (Khắc Nhu) and her mother was Hoan Đỗ. Her paternal grandparents were Phương and Bang Trần. She had two brothers and two sisters, named Kha, Hồ, Lâm and Diêm. She was the second youngest of the five children.