Here's a little summary on what happened
Maxon's selection was postponed because of his parent's death and he immediately became king. Aspen never broke up with America because the selection never happened so America never had money to make him a feast. Aspen decides to not wait for the draft and he marries America. Later on, he gets drafted and dies from a rebel attack in the palace. America finds herself heartbroken. Aspen's mother is unable to support herself and her daughters because of her grieving. America finds that her only option is to sign up as a maid in the palace so that she would have enough money to support Aspen's family.