Seo Yeongsuhap was born into a high-ranking family, the Dalseong Seo clan (), as the daughter of the governor of
Gangwon Province, Seo Hyeong-su, and Lady Kim of the Andong Kim clan. Through her mother, Lady Seo was a great-great-great-granddaughter of
Princess Jeongmyeong and
Hong Ju-won. Thus making her be fourth cousins to
Lady Hyegyeong, and a fourth cousins once removed to her future husband. Through paternal grandfather, Yeongsuhap and the future
Queen Sunwon, King Jeongjo’s daughter-in-law, were third cousins. She was reportedly known for her abilities in mathematics. She was later arranged to marry Hong In-mo of the Pungsan Hong clan, a royal official. They had three sons, , Hong Gil-ju, and , and two daughters, Hong Won-ju (alternatively known as Hong Yuhandang) and Lady Hong. All four became poets as well, and Gil-ju under the influence of his mother also became a notable mathematician. Her third son, Hong Hyeon-ju, married
Princess Sukseon, the only daughter of King
Jeongjo of Joseon, who herself is known for inventing
Kkakdugi, i.e. the diced radish kimchi. ==References==