It also helps to know the context. Craig writes in his blog about how he prayed for this grandmother and how she was miraculously healed. That's why she calls him this. Don't worry, Craig defers the glory to God.
I saw firsthand Craig's Christ-like love for this family. He loves on the kids. He is patient. He breaks bread with them. He takes time for them. The dad loves him. The mom loves him. The kids love him. And the Grandmother adores him.
The grandmother's healing and how Craig has lived as a 'little Christ' among them has opened the door for this family to know Jesus personally. Maybe he is just being like those believers in Antoich who were the first to be called Christians.