At the end of [**Hunger Games Mockingjay 2**][1] we see that Katniss goes home back to her own district followed by Peeta afterwards. 

**Why does she do so? Why not stay at the capital city of Panem and take part in forming the new governing body?** 

I know that she killed Alma Coin who was the president of the rebels but she did so in order to prevent another hunger games. 


  [1]: https://en.wikipedia.org/wiki/The_Hunger_Games:_Mockingjay_%E2%80%93_Part_2