Byblos was responding specifically to what you said here:
From reading what you wrote, it seems you're saying that Mary was the mother of only the physical or human "part" of Jesus.Mary was the physical mother of the human shell that Jesus took on. Period!
Mary was the mother of the person, Jesus Chris, who is God. You are arguing the same thing I was arguing.
Christ's humanity, or human shell as you put it, isn't separate from his divine nature. See Hypostatic Union.