It's so strange that in the age of the internet, we still can't find out how North Koreans live directly from them. It's crazy, but at the same time, it's so fascinating.
Heartbreaking.
In the USA they would be immediately scooped up and placed in a protective foster home of some sort. Teenaged runaways can evade capture and return, but a 5-year-old cannot go trotting around wherever they please. I cannot imagine the fate of a girl in those circumstances.
Surely, this boy could not be surviving without support and guidance from elder allies. I am not sure what "fending for oneself" looks like in NK culture, but I can envision a lot of people taking pity and giving help and handouts of some kind.