Diêm was born in 1903. Diêm'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 Thảo. She was the youngest of the five children.