Earlier on this episode, by promising her nonsensical choice to stick in Woodbury was her effort to guard and look following the innocent citizens, I attempted to defend Andrea. Yet more, I am totally incorrect. Her actual reason behind returning to Woodbury is so she is able to spend a whole episode.
Milton discloses Governor’s actual strategies with Rick and Michonne to Andrea. After being among the very most gullible TV characters, she determines the Governor is insane and it’s the right time to return to her first group. The penitentiary needs to have proceeded because it looks like a huge trek through the wilds and takes her over a day.