Sometimes I wonder if my willingness to respond to questions like this isn't proof positive that I have no discernment or common sense for that matter...
Ah well.
Short answer to your son's question Sandman. Man is not created in the image of God in a physical sense, but in the sense that Man alone in all creation has been endowed with an immortal soul, an eternal spark that reflected the qualities of his Creator. Man in his unfallen state resembled the Creator in that he had the gifts of knowledge, reason, & holiness and thus differed from every other living thing in creation whether it be flora or fauna. In the fall of man (Genesis 3), this image of God (called the Imago Dei) in man was obscured, but not destroyed. Jesus pointed out that the Father is Spirit, and must thus be worshipped not as the idols were with outward and physical offerings, but from the heart, saying to the woman at the well in John 4:24 -
"God is Spirit, and those who worship Him must worship in spirit and truth."
The Bible teaches us that Jesus, being the Son of God, became incarnate, that is he took on our human nature, adding a human body and a reasonable soul to His pre-existing deity - Not that the he eternally had a physical body like ours.
As loathe as I am to deal with the subject, God did not have sexual relations with Mary, Scripture teaches that Jesus was conceived in her womb by the power of the Holy Spirit. The Westminster Confession, summarizing the ancient ecumenical creeds of the church states it well:
The Son of God, the second person in the Trinity, being very and eternal God, of one substance and equal with the Father, did, when the fullness of time was come, take upon him man's nature, with all the essential properties, and common infirmities thereof, yet without sin; being conceived by the power of the Holy Ghost, in the womb of the virgin Mary, of her substance. So that two whole, perfect, and distinct natures, the Godhead and the manhood, were inseparably joined together in one person, without conversion, composition, or confusion. Which person is very God, and very man, yet one Christ, the only Mediator between God and man.
Hoping this is useful to someone out there, I remain, your servant,
SEAGOON