This submission is more suitable for a sub that deals in theology, not history. We do not deal with hypotheses, but questions. Additionally, the immaculate conception refers to the birth of Mary, not Jesus. The Catholic teaching was that Mary's birth was immaculate--she was free from sin--so that she would not pass on sin to Jesus, when she was carrying him in her womb. Mary would not have told Jesus any of this, as the roots of the doctrine dates only to Late Antiquity.