OK so the big Question is, Where is Beth?
By the fourth season, Beth is emotionally stronger, trying many different ways to deal with the loss of hope that grows everyday, realizing that things may someday take a turn for the worse. After dating Zach, she became emotionally distant, preparing herself so that when someone she loved dies, she won't shut down emotionally like she used to in the past. After Zach's death, she spent her time dealing with the new crisis surrounding the prison. Beth kept hope alive, while struggling with herself not to break down emotionally. After her father's death, Beth was distraught but grew stronger and found new strength in herself. Beth became more independent and more skillful at killing walkers. After spending time together with Daryl after the prison assault, Beth's faith becomes stronger, and she believes there is still hope and good people somewhere, even in this cruel world. Ultimately she was kidnapped after being separated from Daryl during a walker attack on the house they were staying in. Her whereabouts are currently unknown.
I think that Beth is alive and well in Terminus. Gareth offered her a deal. She could join their ranks and not become a dinner entree, but only if she promised to never sing again. She agrees. After witnessing what goes down with Rick and company, she hooks up with Morgan (who is also there), and together, formulate a plan to rescue the group in the railroad cars.
What do you think will happen to Beth if she arrive in the terminus? comment what you think.