The central conflict in Mockingjay  by Suzanne Collins revolves around Katniss Everdeen's internal struggle to define her role in the rebellion against Panem.  Although she has people, like Coin, Plutarch Heavensbee, Haymitch, and even Gale and Peeta, constantly giving her advice or trying to mold her into their version of what they think the Mockingjay should be, Katniss dislikes and sometimes outright disagrees with their opinions.  Even President Snow attempts to control Katniss' actions through Peeta:

“It's impossible to be the Mockingjay. Impossible to complete even this one sentence. Because now I know that everything I say will be directly taken out on Peeta. Result in his torture. But not his death, no, nothing so merciful as that."

The main external conflict of the novel addresses the rebellion of the districts against Panem and the ultimate invasion of the Capitol.  The reader ventures with Katniss as she goes on multiple missions as the Mockingjay through the battle zones in the districts and into the Capitol.