Peeta says it will be okay. We have each other. And the book. We can make them understand in a way that will make them braver. But one day I'll have to explain about my nightmares. Why they came. Why they won't ever really go away. (Epilogue.6)
Even twenty or so years after the Games and the war, it takes courage to get through each day. The events Katniss and Peeta witnessed – and the things they had to do in order to survive – have left permanent marks on them, mind, body, and soul. They can try to "make [their children] braver," but that's something they have to do for themselves all the time too.