She holds no known official title in North Korea. The outside world has never heard her voice. The North’s state media has not even named her, referring to her only as the “most beloved,” “respected” or “dear” daughter of its leader.
But intelligence officials and analysts in South Korea are paying close attention to the young woman whom they consider to be her father’s most likely successor.
She is believed to be just 12.
The New York Times analyzed hundreds of images and videos of Ju-ae’s public appearances since her debut three years ago to trace her transformation from a shy girl by her father’s side to a poised public figure who shares center stage with him.
Some analysts say she has largely replaced her mother, Mr. Kim’s wife, Ri Sol-ju, in the role of first lady. North Korea has been ruled by the Kim family since its founding at the end of World War II, making it the only dynasty in the communist world.
South Korean intelligence officials believe that Mr. Kim most likely has two children. There have also been unconfirmed reports that he might have a third child, possibly a son older than Ju-ae. But Ju-ae is the only child who has made public appearances. If she is her father’s designated successor, she would be in line to become the first woman to rule North Korea’s deeply patriarchal and highly militarized society and the world’s newest nuclear power. Mr. Kim is only 41 but, with a family history of heart trouble, preparing a successor makes sense.
Here is a look at Ju-ae’s rise.
Taking the Stage
Ju-ae has undergone a striking transformation in North Korea’s tightly choreographed state media.
Intelligence officials and analysts in South Korea caution against firm conclusions about her future role. But as her profile has risen, she has eclipsed her mother and Mr. Kim’s powerful sister Kim Yo-jong, also once considered a potential successor, as the main female face of the ruling family.
When Mr. Kim and his daughter visited the greenhouse complex, state media called them “great persons of guidance” — an honorific that over the years has been reserved for only North Korea’s top leader and his designated successor.
North Korea also began issuing postage stamps bearing the images of father and daughter together.
“In North Korea, where officials and people are not ready to accept a female leader, Kim Jong-un is making his daughter’s successor status a fait accompli by repeatedly exposing her through state media,” said Cheong Seong-chang, an analyst at the Sejong Institute in Seoul who has written books on Mr. Kim and his family.
A New Look
Ju-ae’s birth and name were first revealed to the outside world by the retired N.B.A. star Dennis Rodman, who met the Kim family during a visit to North Korea in 2013.
When she made her first public appearance in 2022 in a white padded winter jacket, Ju-ae looked no different from the other children of the elites in Pyongyang. But as she has grown, her clothes have become more formal, and she has been transformed into a figure of authority. Her wardrobe now includes tailored leather coats with fur collars and two-piece designer suits.
As her mother has receded from public view, Ju-ae has begun to adopt her sense of fashion.
Her mannerisms and demeanor have also changed. Even something as small as how she claps looks different now than it did two years ago.
“The child who first appeared as a family curiosity is now a polished, rehearsed figure woven into North Korea’s ongoing story of dynastic power,” said Donald Southerton, the author of “Korea 101.” “Each photo, parade walk and salute I see as a carefully staged story of succession, legitimacy and continuity for the Kim dynasty.”
Should a brother emerge, Ju-ae may end up serving as a mere placeholder, said Kang Dong-wan, an expert on North Korea at Dong-A University in South Korea. For now, though, her prominent portrayal is sending a message to North Koreans that the Kim family rule will continue into a fourth generation.
Her Main Inheritance
Mr. Kim chose the launch of an intercontinental ballistic missile, or ICBM, for his daughter’s public debut in November 2022. Since that day, he has taken her to other nuclear-related sites, introducing her to officials involved in North Korea’s weapons programs. He has lauded the arsenal as a major legacy of the family’s rule.
When Mr. Kim himself was being groomed to succeed his father, he first established his authority with the military, the key to maintaining power. Now, by taking Ju-ae to military events, Mr. Kim has been showing her how he handles the top brass.
He has also offered senior military officers opportunities to meet and show loyalty to her, analysts said.
Mr. Kim’s Health
By preparing a successor publicly from an early age, Mr. Kim may be trying to avoid the mistake his father made, analysts say. It was not until after his father had a stroke in 2008 that Mr. Kim was unveiled as the heir apparent.
That led to uncertainty about the younger Mr. Kim. In his early years, he faced skepticism from outside analysts who dismissed him as an inexperienced leader and argued that he would not last long.
That was before Mr. Kim executed his uncle, had his half brother assassinated by his agents in Malaysia and purged several top generals to establish his unchallenged authority.
Now it is primarily Mr. Kim’s health, not his hold on power, that is in question. He is about 5 feet 7 inches and weighs about 310 pounds, according to South Korean intelligence officials. They added that he had unhealthy habits, including chain-smoking, heavy wining and dining, and frequently staying up into the early morning to surf the internet, where he likes to browse weapons sites.
Mr. Kim is believed to have cardiovascular issues, which contributed to the deaths of both his father and grandfather.
One advantage to grooming a successor early, even a young child, is leverage against his American and South Korean adversaries, said Sung-Yoon Lee, the author of “The Sister: North Korea’s Kim Yo Jong, the Most Dangerous Woman in the World.”
“It tells them: ‘We have all the time in the world, while you are bound by term limits of four to five years,’” Mr. Lee said.