"From the protocol point of view, such as this woman's place and table settings, it is highly likely that she's his wife and first Chairman Kim must actually be married," the source said on condition of anonymity, referring to Kim's title as first chairman of the powerful National Defense Commission.
The unidentified woman first appeared in state media on July 5 when she was seen seated right next to the leader during a music concert. Analysts said at the time she might be either Kim's wife or a younger sister.
The stylish-looking woman was seen again on July 8 paying tribute to late North Korean founder Kim Il-sung, bowing deeply while standing next to the leader, as uniformed North Korean military officials raised their hands in salute behind the couple dressed in black.
North Korean leader Kim Jong-un talks to children during a visit to a kindergarten in Pyongyang as an unidentified woman looks on in North Korean TV footage shown on July 15, 2012. (Yonhap)
On Sunday, the North's state TV released footage showing Kim bending over to talk to children during the kindergarten visit as the woman, clad in a yellow polka dot dress and a luxurious-looking white cardigan with a stylish hairstyle and high-heeled shoes, looked on next to him.
North Korean officials accompanying the leader were seen standing a few steps behind them.
State media did not identify who she was, but her act was seen as that of a first lady.
Few personal details are known about the young North Korean leader, including his marital status and exact age, except that he studied in Switzerland when he was young. Kim assumed control of the communist nation after his father Kim Jong-il died in December.
Cheong Seong-chang, a senior fellow at the Sejong Institute, said the woman appears to be Kim's wife, and the North appears to be releasing the images of her to dispel any misgivings among the North Korean public that their leader is too young.