News outlets that published the story have not shown any sources.
Also, the photo above used by The Sun is from a commemoration ceremony of Kim Jong-suk in 2015, showing government officials placing a wreath on her bust.
Although, in the North Korean constitution there is freedom of religion, this right cannot be exercised in practice. Praying in the public space without a permission from the official authorities can be punished with prison.
In the capital Pyongyang, some hotels, shops and restaurants catering to the elites and the foreigners have christmas trees but these displays are free from any explicitly religious symbols.
Kim Jong-suk was born December 24th, in the Christmas eve. She have fought against the Japanese and she is the first five of the Kim Il-sung, the founder of North Korea.