Jong Un himself is the 3rd son as Jong Il passed over his first two as unsuitable. The oldest was assassinated and the second plays in a band and avoids politics.
Going to guess that Kim Un’s oldest child is also considered unsuitable for some reason.
[...unsuitable for some reason.]
Puberty. She is more interested in Kpop boy bands than ruling over skinny peasents.
I think Kim Jong Un went to school in Switzerland. I wonder if the oldest is doing something like that.