I think the most blame should be put on the mother who did not ask anyone for help though I would not be surprised if she was suffering from depression that contributed to her death:
Han Sung-ok, 42, seemed determined to pick through nearly every lettuce on the market stand. She turned each one over and examined it while her six-year-old son clambered on the fence nearby.
The vegetable seller in the southern Seoul suburb looked on, annoyed. This was one picky customer and she didn’t even buy a lot of vegetables – only one or two items for as little as she could pay. On this occasion it was a lettuce for 500 won (about $0.40; £0.33).
Uttering only a few words, Han handed over her money and left with her son.
Just a few weeks later, both were dead.
Having fled food shortages in her native North Korea and dreaming of a new life, Han and her son are believed to have starved to death in one of the wealthiest cities in Asia. Their bodies lay undiscovered for two months until someone came to read the water meter and noticed a bad smell.
Mother and son were found apart on the floor. The only food in their tiny rented apartment was a bag of red pepper chilli flakes.
BBC
You can read the whole thing at the link, but she definitely had a hard life and trouble adapting to South Korean culture. People in the government probably should have done more to check on her welfare, but ultimately if she would have reached out to defector organizations or even a local church she could have gotten help instead of starving to death.
