She is not a mother only of His human nature but of His whole eternal person.
So are you saying
1) that Mary is as eternal as God, making her a Goddess in her own right orEither way puts you in a state of complete heresy. Only if make some level of distinction between Yeshua's God-nature and Man-nature--while, of course, acknowledging that Yeshua was fully both--do you avoid this trap.
2) that God is not really eternal, but began to exist at Jesus' conception?
I am saying the exact same thing the Council of Ephesus is saying. Motherhood is of a person, not of a nature. Wrap you mind around it.