>>How could He have a mother, since He is eternal and the Creator of all things?<<
The answer is quite simple actually. Time flows like a river. Eternity is an ocean. God can inject himself in the past as easy as Dr Brown in Back to the future could inject himself in the past.
Easier actually, because time passage is a mere artifact of Gods created universe. Heaven is a different place.
So much of this parsing of words reminds me of the folks 2,000 years ago who spent all their waking hours doing the same and trying to trap the serfs in some way thereby in order to heavy-handedly increase the leaders’ control over them; their so called lofty status above them . . . etc.