"The main Raveler, is [student name or pseudonym]. [a Ravelry membername] If you can help him out with patterns or how to’s or just encouragement, that would be great!"
Pardon my cynicism, but this smells as fishy as three-week-old bait. You say the message was random and unexpected. I wonder how many other men on Ravelry received it. I wonder if the "teacher" is really a teacher or someone looking for friendship (or something else) in a roundabout and rather creepy way. I wonder if the message-sender is male or female and really is in Saudi Arabia.
I agree with everybody who says that third graders should not be on social networking sites (assuming that third grade means about 8 years old, as it does in the US). But the bottom line is: are you interested in mentoring a kid you don't know and "helping out with patterns or how to's or just enouragement?" If not, just say so politely and leave it at that. You are also under no obligation ot respond to an unsolicited message; just ignore it and it will go away.
However, I think the responsible thing would be to forward the message to Casey at Ravelry. If young kids are participating in the groups and forums, he should be aware of it. By the way, have you checked the profile of the membername you were sent? Just click on "People" and type it in. The results might be interesting.
BaaBaa on Ravelry