The photo shows Ri accompanying North Korean leader Kim Jong-un at the governing family mausoleum where the embalmed body of late leader Kim Jong-il is laid. Feb. 16 was the anniversary of the birth of the late leader, who died from heart problems in December, 2011.
Ri appeared in a tight dark skirt suit, designed to emphasize her slim waist, and short curly hair.
"We assume (she) may have given birth," a government source said in the first-ever confirmation by a government official that Ri may have given birth.
Another intelligence source also said "The released photo suggests the possibility of childbirth." The intelligence source added that the process to confirm the suspicion is underway.
Media speculations said Ri was pregnant when she appeared in a wide-bellied yellow coat to watch a musical performance on the New Year. The Sunday photo again stirred media speculations that she has given birth.
South Korea's spy agency, the National Intelligence Service, previously said last year that the couple which leads the communist country may already have one child.