Given the events recorded in the infancy narratives in Matthew amd Luke. hos mother must have had a clue. Or don’t you believe these are true?
First remember that the gospels were written after the Lord has ascended. The writers would have had great difficulty severing the the level of understanding that they had themselves achieved from their stumbling confusion at the start of his adult ministery.
There is some evidence that Mary's sister Elizabeth had some understanding of what was taking place, but I see little evidence that Mary or Joseph understood more than that the child that they were raising was to be a King of the House of David. If you will remember, at one point the Lord came to despair at her lack of understanding during his adolescence, saying "what am I to do with thee woman?"