Safety

I think Katniss thinks by safety when she left the arena is that she wouldn't be hunted and killed. She feels freedom again outside of the arena. She was the winner along with Peeta and she would think she wouldn't have to participate in another hunger games. I also think she feels safe because the acting of love continues and she just have to act in love. Everything would fit and it would be normal again. 
The word safety to me is being protected by your family or friends. They will be here to help you and take care of your problems. In the other hand, safety means that happiness in me that you wouldn't be dead tonight. Fear isn't overpowering you. I feel happy that I could be safe and odds of unsafe is little. Even though safety cannot be all safe, we tend not to worry about the bad side. We think if we are protected enough, we are safe.