The future Queen later married Grand Prince Suyang at the age of ten in 1428, on the thirteenth day of the twelfth lunar month in the tenth year of King Sejong's reign.
There was a lot of controversy surrounding the marriage as it was widely believed that Grand Prince Suyang was supposed to marry her elder sister but instead preferred her for a series of political and social reasons.
Grand Prince Suyang was always seen as a political threat even while he was young to his older brother the future King Munjong because the latter appeared to be much stronger and more competent as a leader which had worried his father to the point of choosing him a wife from a less prominent but dignified family and what was even a conciliatory role to restrain Suyang's ambition was the fact that his principle wife had only received basic education which made her somewhat illiterate based on the fact that she could barely read Hanja.
As the Grand Internal Princess Consort Nakrang, she bore Sejo's sons Prince Dowon and the Future King Yejong and helped her husband in the first coup in which he overthrew Kim Chongsŏ and installed himself as the Chief State Chancellor.
The Queen was very wise and intelligent, had great knowledge of all affairs within and outside the palace while she was quick-witted and cautious, very virtuous and calculative Sejo once praised her to be very diligent in all issues big and small and more than once acted with high regard of her position as a mother of the nation and the head of the Naemyeongbu.
She engineered a series of political marriages within the Royal families and established a strong network of eunuchs and court ladies along with spies in the palace which enabled her to play a conciliatory role for her husband's position.
But nonetheless, the Queen had her way because the former Crown Princess Su at the time was powerless in rank and the influence of the Cheongju Han clan on Joseon Dynasty politics was at the Genesis of its wane.
Because Yejong was weak and sickly, the officials supported the Queen Dowager, who being the most influential elder in the palace, King's mother and political protectress, to pursue an unofficial regency.
Queen Dowager Jaesong oversaw all civil and military matters on behalf of the King and this further strengthened her political footing by appointing able Ministers, and members of her family, to senior official positions until she came to dominate the entire court.
The Queen eventually relinquished the role when Yejong's health showed great improvement as it had started to stirr the strongly Confucian Joseon society and had seemingly attracted too much censure from the scholars of Sungkyunkwan.
In 1469, roughly a year since King Yejong had ascended the throne and had showed signs of recovery, he died suddenly at the age of 20 without having named his successor and another fierce strife ensued within the court.
Diplomatic relations with the Ming Dynasty peaked with trade flourishing between the two countries and furthermore, a significant move was made for the commoner farmers to receive the right to cultivate fields that had originally belonged to the military.