Answer:
When she's in the Arena, Katniss begins to see her sister, Prim, in a twelve-year-old tribute named Rue, whom she vows to protect in the Arena as much as she can. It is because of her love for Prim that Katniss loves Rue and goes to great lengths to attempt to protect her.
The relationship Katniss and Gale have in the book the Hunger Games by Suzanne Collins is a very trustworthy friendship.
