Kim Jong-un’s younger sister, Kim Yo-jong, is expected to take up an important role in North Korea’s core leadership as the secretive country gears up for a rare party congress this weekend.

South Korea’s news agency Yonhap has quoted experts as saying that Yo-jong may take up a minister-level post within the ruling Workers’ Party of Korea.

The move will likely be seen as part of a larger plan by Kim Jong-un to cement power within his party and over the country.

According to North Korea Leadership Watch, a website run by scholar Michael Madden, Kim Yo-jong is the youngest daughter of late leader Kim Jong-il, and shares the same mother as Jong-un and brother Jong-chol.

Born in 1987, Kim Yo-jong is said to be very close to Kim Jong-un, who is four years older than her. The two of them lived and studied in Berne, Switzerland at the same time.

Kim Yo-jong is reportedly married to the son of Choe Ryong-hae, the powerful party secretary.

Her main job has been to protect her brother’s image, taking up a key role in the party’s propaganda department in 2014.

Kim Yo-jong is said to manage all his public appearances, including his itineraries and logistics, as well as act as a political adviser.

Kim Jong-un’s sister has sporadically been in the spotlight in recent years, appearing at the state funeral of her father in 2011 and the election of her brother in 2014, and occasionally seen trailing her brother in state media pictures.

In October 2015, Kim Yo-jong she was rumored to have been sacked from the propaganda department by Jong-un for doing a poor job.

However, observers believe that she is still destined for a top job in the leadership, with a place said to be carved out for her as early as 2008, when major succession planning was conducted following Kim Jong-il’s deterioration in health.

Kim Yo-jong was even speculated to be a possible, though unlikely, candidate to take over from her brother when Jong-un disappeared from public view for a prolonged period in 2014.

She has been described as having a sweet, good-natured disposition, with a bit of a tomboy streak in he.

However, reports say Kim Yo-jong also has had a sheltered upbringing, and other members of the Kim family have not interacted with her much.

School officials in Switzerland have said Kim Yo-jong was over-protected by the coterie of guards and caretakers – she once reportedly had a mild cold and was immediately pulled from school and taken to the hospital.