Answer:
Well, she has been hunting for years now.
Explanation:
For one, that's against their law. Poaching as they call it. She knows how to work a bow and arrow, far beyond a regular tribute, she knows how to "starve" herself, so she's cut out for it. She also knows foraging.
These are against society, because all those things, contribute to her being the Mockingjay. Which is, a symbol of rebellion. Especially, with the Nightlock.
