In this scene, Gale kisses Katniss unexpectedly. From this, we can tell that there have been hidden feelings all along, perhaps. Being away from her for so long, and seeing her with another guy, Gale likely realizes that his love for Katniss is what's kept his family and her's safe and fed.
Example #4: pg. 188
Peeta is most important. He has what it takes to get through this, mentally and physically.
In this scene, the new head peacekeeper of District 12 whips Gale ferociously as the rest of the coal miners look on. This goes on in the middle of Town Square until Katniss comes to his rescue, sacrificing her own well-being. This further proved to the district that Katniss is a team player.
Example #5: pg. 301-302
MAGS! WHERE ARE YOU GOING?
Katniss, get back here! What are you doing
In this scene, Katniss finds out that she'll be a part of another Hunger Games: the Quarter Quell. Her and her family react to the news with panic. The reason Katniss was ever even involved with the Games was as sacrifice for her sister, Prim. Now, she's being taken away from her family again, which will play into her hate towards the Capitol, and fuel her dreams of rebellion.
Example #6: pg. 339-340
I MUST save Prim!
In this scene, Katniss confirms that she does not have any hope of being victorious in the Quarter Quell. Instead, we learn that she plans to do everything in her power to keep Peeta alive during the Games. Katniss is no stranger to sacrifice, especially when it's for her loved ones.
Katniss! Come on!
In this scene, Mags is the group's weakest link. Unfortunately, the poor, sweet, old lady is only slowing the group down. Realizing that they would all be dead soon because of her, the loving old woman did something incredibly brave. She walked in to the acid, and eliminated herself to save the others.
Katniss cares so deeply about Prim that the Gamemakers know enough to use it against her during the Games. This goes to show that with all of the good love can do in this book, some characters will find ways to take advantage of that.