His aunt is a general and conceivably might make a bid for power.
Thanks for giving me nightmares of a female totalitarian dictator.
There have been plenty in history.
Sure, there have been plenty of thuggish women as leaders and women as powers behind the throne, but to date there have been no "Generalissimos" or "Great Leaders" or Glorious Generals with a chest full of medals of the fairer gender, at least not since mass media was introduced.
Surely Indira Ghandi comes at least close.
Anyway, with regards to the original question, turning Kim Jong-un into a puppet would be far more valuable to any general than overthrowing him.