Why was Taylor heartbroken when she had to leave Estevan and Esperanza at the church?

When Taylor prepares to leave Estevan and Esperanza, she deliberately awakes Turtle so that the baby girl can see them before going, for Taylor says "it's happened too many times that people she loved were whisked away from her without any explanation." Everyone is exhausted, so goodbyes are nearly impossible. Estevan puts his hand on Taylor's arm, and she asks what he will do. He answers: "Survive." He tells her to think of him and Esperanza back in Guatemala "when the world is different," but she says that the world will never be different. He touches her cheek as she prepares to cry. He says that he can send news by way of Mattie. Estevan and Taylor discuss how transferring custody in the office was a catharsis for Esperanza, and now she seems happy. He says that "in a world as wrong as this one, all we can do is to make things as right as we can." Taylor thinks that all four of them had buried someone they loved in Oklahoma.

Oh, and let's not forget she's in love with him!