Upvote:0
It is not wise to "assume the Gospels are eye-witness accounts."
At most, only two Gospels--Matthew and John--were.
As to how certain events in Jesus' private life could have been recorded, I think a quote from one who was an eye-witness, and of the Twelve, suffices:
Upvote:1
Using Occam's razor, there is no reason to expect a supernatural medium for the transmission of this information to the disciples. Jesus spent three years with his disciples. They had plenty of time to sit around the campfire, telling stories.