If Kim Jong Un dies, will his sister take charge of North Korea?

North Korea has so far remained tight-lipped about media reports suggesting that leader Kim Jong Un may be unwell after intense international speculation over his health was sparked by reports that he was gravely ill after a cardiovascular procedure. There's also a renewed worry about who's next in line to run the country if Kim Jong Un dies. Speculation about his health problems spiked after a CNN report earlier this week said that Washington was looking into intelligence that Kim Jong-un was in "grave danger" after a surgery.

Kim Jong Un was last seen in state media on April 11 presiding over a political bureau meeting of the ruling Workers` Party, calling for strict measures against the coronavirus pandemic.

The nuclear-armed nation has been ruled by the same family for seven decades. Questions about Kim's health flared after he skipped an April 15 commemoration of the 108th birthday of his grandfather, North Korea founder Kim Il Sung. It's North Korea's most important event, and Kim, believed to be 36, hadn't missed it since inheriting power from his father in late 2011.

Kim is the third generation of his family to rule North Korea, and a strong personality cult has been built around him, his father and grandfather. The family's mythical, Paektu, bloodline, named after the highest peak on the Korean Peninsula, is said to give only direct family members the right to rule the nation. That makes Kim's younger sister, senior ruling party official Kim Yo Jong, the most likely candidate to step in if her brother is gravely ill, incapacitated or dies.

Believed to be in her early 30s, Kim Yo Jong is in charge of North Korea's propaganda affairs, and earlier in April was made an alternate member of the powerful Politburo. She has frequently appeared with her brother at public activities, standing out among elderly male officials. She accompanied Kim Jong Un on his high-stakes summits with US President Donald Trump and other world leaders in recent years. Her proximity to him during those summits led many outsiders to believe she's essentially North Korea's No 2 official.

Born in September 1987, Kim Yo Jong is the youngest child of Kim Jong Il, former North Korean leader. Her mother was Ko Yong Hui, who was the former leader’s second mistress.

She was 9 when she was sent to Berne, Switzerland, where she attended elementary school. It was here that she forged a close bond with her older brother Kim Jong Un. The pair shared a private home and were attended to by their own chef, housekeeping staff, and bodyguards, according to new website Vice.

After returning to North Korea in 2000, her future as part of her family’s political dynasty was signalled by 2002, when her father told foreigners that his youngest daughter was interested in politics and wanted a career in North Korea’s political system. In 2007, she graduated from Pyongyang's Kim Il Sung University with a computer science degree and joined the ruling Workers’ Party.

She became a close aide to her father after he suffered several strokes in 2008. Over the next few years, she helped plan her brother’s ascension to the position of Supreme Leader.

However, the fact that North Korea is an extremely patriarchal society has led some to wonder if Kim Yo Jong would only serve as a temporary figurehead and then be replaced by a collective leadership similar to ones established after the deaths of other Communist dictators.

Some analysts have also suggested that collective leadership, which could end the family's dynastic rule, could also be possible. A collective leadership would likely be headed by Choe Ryong Hae, North Korea's ceremonial head of state who officially ranks No. 2 in the country's current power hierarchy. But Choe is still not a Kim family member, and that could raise questions about his legitimacy and put North Korea into deeper political chaos, according to other observers.

Other Kim family members who might take over include Kim Pyong Il, the 65-year-old half-brother of Kim Jong Il who reportedly returned home in November after decades in Europe as a diplomat. Kim Pyong Il's age could make him a reasonable frontman for collective leadership by the State Affairs Commission and regent for the preferred next-generation successor said a professor at Ewha University in Seoul. 

Kim has disappeared from coverage in North Korean state media before. In 2014, he vanished for more than a month and North Korean state TV later showed him walking with a limp. Speculation about his health has been fanned by his heavy smoking, apparent weight gain since taking power and family history of cardiovascular problems. When Kim Jong Un`s father, Kim Jong Il, suffered a stroke in 2008, South Korean media reported at the time that Chinese doctors were involved in his treatment along with French physicians.

Kim came to power after his father Kim Jong Il died in 2011 from a heart attack.