How does Agatha help John and Lara?

When she travels with John to his and Lara's house, Agatha finds herself in Sean's old room and she is overcome with a different kind of vision than those to which she is accustomed. Instead of seeing the sure future, she imagines a hypothetical future in which Sean had lived. Weeping, she tells Lara and John all about the young man Sean would have grown into had he lived. This emotional vision gives Lara and John a sense of closure, a way of communing with their son who they lost. In this moment, Agatha serves as a kind of spiritual advisor, an angel sent to give comfort to the grieving and despondent couple.