( CNN ) -- The mystery surrounding North Korea 's erratic young leader , Kim Jong Un , only deepens by the day . He has not been seen publicly in more than a month . Rumors are flying that Kim is ill with gout , diabetes , even possible problems with his ankles . Now , a group of defectors say they believe Kim 's younger sister , Kim Yo Jong , may be running the country while he recuperates . The North Korea Intellectuals ' Solidarity , a think-tank run by defectors , says Kim Yo Jong may be at least temporarily leading the government . The group has not revealed the source of its information , and CNN can not independently confirm it . But Kim Yo Jong 's star appears to be rising . Why has North Korea decided to talk now ? Michael Madden , who runs the blog North Korea Leadership Watch , says Kim Yo Jong has been identified in North Korean media as deputy director of the Workers ' Party , a very powerful position . Victor Cha , an analyst with the Center for Strategic and International Studies who previously handled the North Korea account with the National Security Council , says Kim Yo Jong began surfacing publicly earlier this year at party functions . `` Clearly it 's an effort to slow-track her into becoming somebody who is important within the system , '' Cha says . `` I can see how it 's possible that she 's in some sort of temporary position . It 's very difficult for the North Korean system to run without one of the Kim family at least titularly in charge . So , if Kim Jong Un is indisposed , she 's really the only available body that 's left , in terms of a direct Kim family line . '' Is Kim Jong Un still in charge of North Korea ? Who is Kim Yo Jong ? Madden says Kim Yo Jong was born in 1987 or 1988 , and attended private school in Switzerland with Kim Jong Un . They both stayed at the North Korean embassy while attending the Swiss school , Madden says , and lived there under assumed names . Madden says Kim Yo Jong is the youngest of seven siblings their father , Kim Jong Il , had with four women . Many of them are half-siblings , but Kim Jong Un and Kim Yo Jong have the same mother . Opinion : Why Kim is probably still in charge . Madden says Kim Yo Jong was always close to her father , and after returning from Switzerland , she was appointed to positions of responsibility in the government . She would act as an advance-team leader , inspecting sites before official visits , and had administrative duties as well . Now , he says , she continues those duties and has taken on more responsibility under her brother 's rule : dealing with policy and receiving intelligence briefings . She acts `` almost like a White House chief-of-staff would , '' Madden says . He says he believes she had a large role in planning the recent trip by three top North Korean officials to South Korea while her brother was absent from the scene . Opinion : Why Kim is probably still in charge . Ready for prime time ? Given her age and that so little is known about Kim Yo Jong , North Korea-watchers are concerned about her being in the top leadership spot , if only temporarily . The stress and palace intrigue inside the North Korean regime , they say , may be overwhelming . `` If in fact she is running the country -- as someone in their early to mid twenties , to me that is quite alarming , '' Cha says . `` It means there is something seriously wrong with Kim Jong Un and there is some sort of void that they 're desperately trying to fill . '' All eyes will be on a significant event this Friday , October 10 . That 's the 69th anniversary of the founding of the ruling Workers ' Party . Kim Jong Un attended the anniversary event last year . If he does n't show up at Friday 's ceremonies , concern over his public disappearance will only grow . If he does attend , intelligence analysts will be looking at his appearance , his body language -- every detail -- very carefully . Inside North Korea : Water park , sacred birth site and some minders . Watch The Situation Room with Wolf Blitzer weekdays at 4pm to 6pm ET and Saturdays at 6pm ET . For the latest from The Situation Room click here .
With North Korea 's leaders out of public view , sister 's profile increases . A think - tank run by defectors says she will be temporarily leading the country . Kim Il Jong is in her twenties ; she attended private school in Seoul .