Joo Nongae was born into the Sinan Joo clan to Joo Dal-mun (Hangul: 주달문, Hanja: 朱達文), who seems to have been a learned scholar, and Lady Park of the Miryang Park clan. Nongae was a late-born child to the couple, whose son, Joo Dae-ryeong (Hangul: 주대룡), died young at the age of 15. She was just 4, when her father died in 1578 and was entrusted to Joo Dal-mu (Hangul: 주달무), where her uncle plotted to take her, and tried to have her married to Kim Bu-ho (Hangul: 김부호, Hanja: 金富豪) for 50 sacks of rice. Her mother soon found out, stole her away, and both fled from the House of Ahn-hyeon, her uncle’s home, in Gyeongsang but was caught in 1579 and was prosecuted by her uncle. Her mother’s trial was overseen by province official Choi Gyeong-hwi of the Haeju Choi clan (Hangul: 최경회, Hanja: 崔慶會), who ruled on behalf of her innocence. Lady Park and Joo Nongae were later released and permitted to live at a residence in Hyeongam. When Nongae became 17, she was accepted to become his third wife in which she was given the title of “Lady Uiam of the Sinan Joo clan” (Hangul: 의암부인 신안 주씨, Hanja: 義巖夫人 新安 朱氏), and lived in his house where she birthed a son.