It is the first known international appearance by the teenager, who has attended multiple North Korean weapons tests alongside her dad, and analysts say it is a clear signal of her importance in the Kim dynasty's succession planning.

Here is what we know about her:

- Who is she? -

Ju Ae was first publicly introduced to the world in 2022, when she accompanied her father to the launch of an intercontinental ballistic missile.

But it was former NBA star Dennis Rodman who first revealed to the world Kim had a daughter.

According to Rodman, during his 2013 visit to Pyongyang, Kim introduced him to his wife Ri Sol Ju and a baby girl, saying "that's my daughter."

Pyongyang's state media have never identified her by name, but South Korean intelligence says she is Ju Ae, the daughter of Kim and his wife, who they believe married in 2009.

- How has she appeared publicly so far? -

In recent years, North Korean state media have referred to her as the "the beloved child," or "the esteemed child".

Also in state media, North Korean adults have been shown bowing deeply before her.

At recent public appearances, she has often walked ahead of both her aunt -- powerful regime spokeswoman Kim Yo Jong -- and mother, linking arms with her father, whispering to him, and holding hands.

Kim has even been seen letting his daughter enter a car before him.

Ju Ae has also drawn attention for her taste in luxury fashion, appearing in Gucci sunglasses and Cartier watches, while at times mirroring her father's distinctive style, donning matching leather jackets and dark glasses.

- Is this her first trip abroad? -

Her trip to Beijing is her official first trip abroad with Kim.

"She has sequentially appeared at military and diplomatic events, including a Russian Embassy function," Yang Moo-jin, former president of the University of North Korean Studies in Seoul, told AFP.

"But by now accompanying Kim to a 'brother nation's' Victory Day celebration, she is effectively making her formal debut on foreign soil," said Yang.

With the transition from appearances on a domestic stage to an international one, this may be the "final gateway toward succession," added Yang.

- Why does it matter? -

Experts see that this is a calculated move by the Kim family, mainly to give Ju Ae some crucial international exposure.

"This is not a simple family trip but in effect a 'debut as successor'," Lim Eul-chul, a professor at the Institute for Far Eastern Studies at South Korea's Kyungnam University, told AFP.

"Past precedent shows a pattern of heirs consolidating their status through visits to China or international events to gain legitimacy from socialist powers," said Lim.

For example, Kim Jong Il -- Kim Jong Un's father and the designated successor to his own father, Kim Il Sung -- met Xi Zhongxun, the father of China's leader Xi Jinping, in 1983 in Bejing.

"Ju Ae's case fits this trajectory," said Lim.

- Could she really be Kim's successor? -

In 2024, South Korea's National Intelligence Service acknowledged for the first time that Ju Ae is likely to be the next successor.

"Based on an overall analysis of Kim Ju Ae's public appearances and the level of protocol accorded to her since her emergence, she currently appears to be the most likely successor," said Cho Tae-yong, then-head of Seoul's spy agency.

The confirmation was a shock for some, as the South Korean government long said that as North Korea is a male-dominated society, it was "premature" to regard Kim Ju Ae as the successor.

But her appearances tell a different story, said Cheong Seong-chang at Seoul's Sejong Institute.

"At a military parade Ju Ae's white horse appeared second in line after Kim Jong Un's, which can be seen as evidence pointing to her role as successor," said Cheong.

"North Korea has also issued stamps featuring the pair, and high officials kneeling before her are also proof," he added.