In Chapter 21, how does Katniss get through the night?

Katniss gets through the things she needs to do by distracting herself with thoughts of home.... her mother and sister. Her thoughts, however, are not distracting, they're actually worrisome.

Just accept it will be a bad night, I tell myself. I try not to, but I can’t help thinking of my mother and Prim, wondering if they’ll sleep a wink tonight.