The love affair that Kim Yo-jong, sister of North Korea’s leader, enjoyed at the Winter Olympics in South Korea has not ended now that she is back home.

Kim is one of her brother’s must trusted aides, but in a country where top aides can have notoriously short life spans - even when they are blood relatives of the North’s leaders - little can be taken for granted.

But her brother, Kim Jong-un, let the world know how he felt about his sister’s rare visit to the South: When his private jet carrying her home landed this week, a military band and honour guard were waiting for her at the airport in Pyongyang, the North Korean capital.

If Kim Jong-un sent his sister to the Olympics to mount a “charm offensive,” as US officials feared, she did her job. Her visit was still getting warm reviews in the South on Monday.

Just a few months ago, North Korea was regarded as nothing but a menace, rattling the region with nuclear and missile tests and staging bloody political purges at home. Almost overnight, with friendly smiles and messages of reconciliation, Kim Yo-jong managed to help soften her country’s image among South Koreans, at least for the moment.

She delivered her brother’s surprise invitation for President Moon Jae-in of South Korea to visit the North for a summit meeting, and Moon met her four times during her three-day trip. She held her chin up when she met political leaders and faced crowds in the South.

Her light makeup and modest, even prim clothes were a contrast to those of her fashionably dressed sister-in-law, Ri Sol-ju. “I can’t speak very well in public,” Kim said “shyly” when she was asked to give a toast during a dinner at a five-star hotel in Seoul, according to South Korean officials who were present.

Kim Jong-un “expressed satisfaction” after his sister briefed him Monday about her trip to the South.

“It is important to continue making good results by further livening up the warm climate of reconciliation and dialogue created by the strong desire and common will of the North and the South with the Winter Olympics as a momentum,” Kim Jong-un said, according to the North’s official Korean Central News Agency on Tuesday.

Kim Yo-jong is said to have told the South Korean leader that if he and her brother meet, “the North-South relations will improve so fast that yesterday would seem a distant past.”

“I wish I could see you again in Pyongyang soon,” she told Moon at a luncheon on Saturday, according to South Korean officials. “I wish that Your Excellency President will leave a mark for future generations by playing a key role in opening a new chapter for reunification.”

Vice President Mike Pence, who was leading the US delegation to the Olympics, warned that the North was trying to “hijack the message and imagery of the Olympic Games” with its “propaganda” and a “charm offensive.” Pence mounted a counter-propaganda campaign of sorts, meeting defectors from North Korea and bringing with him the father of Otto Warmbier, an American university student who died last year shortly after he was released from months of detention in the North.

But his efforts did little to stop the hoopla over Kim Yo-jong.

“Kim Yo-jong from the North was a nuclear bomb with a smile,” a conservative newspaper columnist wrote, lamenting the Moon government’s treatment of a member of a family condemned by the United Nations for widespread human rights violations.

Lee Sung-yoon, a Korea expert at the Fletcher School of Law and Diplomacy at Tufts University, said, “Trump and Pence will come across more and more as grumpy old men as Kim Jong-un continues to sharpen his knife and his sister flashes that mysterious smile.”

South Korean media scrutinised every detail, including style of dress and handwriting, of Kim Yo-jong, the first immediate member of the Kim family to set foot in the South. During a government briefing in Seoul on Monday, a reporter asked whether Kim Yo Jong was pregnant, saying she appeared to have a slight baby bump.

In South Korean media, Kim Yo-jong was nicknamed “Princess” or “North Korea’s Ivanka” because of her influence with her brother. She was often compared to Ivanka Trump.

North Korea Military Parade Show all 6 1 /6 North Korea Military Parade North Korea Military Parade In this image made from video released by KRT on Feb. 8, 2018, a military parade is held at Kim Il Sung Square in Pyongyang, Thursday, Feb. 8 2018, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade This screen grab taken from North Korea's KCTV on February 8, 2018 shows members of North Korea's military taking part in a parade, with missiles being displayed, in Kim Il Sung Square in Pyongyang. North Korea staged a military parade in Pyongyang on February 8 to mark the 70th anniversary of its armed forces, in a show of strength just a day before the Pyeongchang 2018 Winter Olympic Games open in the South. / AFP PHOTO / KCTV / KCTV / -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / KCTV" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESKCTV/AFP/Getty Images AFP/Getty Images North Korea Military Parade In this image made from video released by KRT, North Korean soldiers march during a military parade in Pyongyang, Thursday, Feb. 8 2018. North Korea held a military parade and rally on Kim Il Sung Square on Thursday, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade In this image made from video released by KRT on Feb. 8, 2018, North Korean leader Kim Jong Un, right, inspects honor guards, along with his wife Ri Sol Ju, center, during a military parade in Pyongyang, Thursday, Feb. 8 2018. North Korea held a military parade and rally on Kim Il Sung Square on Thursday, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade In this image made from video released by KRT on Feb. 8, 2018, North Korean leader Kim Jong Un, center, watches the military parade in Pyongyang, Thursday, Feb. 8 2018. North Korea held a military parade and rally on Kim Il Sung Square on Thursday, just one day before South Korea holds the opening ceremony for the Pyeongchang Winter Olympics. (KRT via AP Photo) AP North Korea Military Parade This screen grab taken from North Korea's KCTV on February 8, 2018 shows North Korean leader Kim Jong Un speaking during a military parade in Kim Il Sung Square in Pyongyang. North Korea staged a military parade in Pyongyang on February 8 to mark the 70th anniversary of its armed forces, in a show of strength just a day before the Pyeongchang 2018 Winter Olympic Games open in the South. / AFP PHOTO / KCTV / KCTV / -----EDITORS NOTE --- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / KCTV" - NO MARKETING - NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS - NO ARCHIVESKCTV/AFP/Getty Images AFP/Getty Images

For his part, Moon, the South Korean leader, responded with caution to Kim Yo-jong’s overtures. He is a strong advocate of dialogue with North Korea but faced doubts that another summit meeting with North Korea would help end its nuclear weapons programme.

“Although the first step towards a peaceful resolution of Korean Peninsula issues has been laid, discrepancies in the positions regarding the North Korean nuclear issue still remain and there is currently no visible progress in denuclearisation of the Korean Peninsula,” his government said Monday in a statement.