“-—obedience to God”.
This is the key.
I think that is the essential part of understanding the God-designed role that Mary played in salvation history. She was the template—the paradim—the role model—(how ever one wants to phrase it)—of the person of faith, the obedient servant of the Lord, the first believer, the archetype for us to see what it means to believe, to live and move and have our being in Christ Jesus, to walk that narrow path with Him to eternity. She is His mother.
How can anyone thinking rationally not accept this?
This is the key question, if we are into the rational thinking. What prevented God from sending the Christ down sooner? The answer is, Mary wasn’t born yet. To produce the Theotokos was the purpose of the Old Testament salvation history.
That's nice to believe but, due to the absolute void of anything else about Mary in the Bible, I don't think it's correct. If it were correct, there would be numerous mentions of it.