I don’t think that was really the foundation of the doctrine. Like many doctrines, it was something that existed in oral tradition and the belief of the first Christians, and was later “codified,” if you will, in a doctrinal formulation. The canon (of Scripture) obviously came after the belief in Mary’s perpetual virginity, so this was probably something that was known to or circulating in the early Christian world, and was not something retroactively extracted from the written Scriptures after they had been solidified and approved by the Church.
Your sequencing narrative is likely plenty correct . . . though I wouldn’t say “known.”
Just be at a Pentecostal special meeting where Holy Spirit moves in very persistent dramatic power and miracles.
Watch then, how the faithful treat the servant of God through whom Holy Spirit has moved.
Wouldn’t surprise me at all that SOME around the time of the early church would humanly elevate Mary in a list of ways.
Doesn’t mean God did.
And, as we have seen, as late as 1940’s . . . such elevation was still being . . . embellished, added to etc.
That fact alone indicates to me the level of nonsense involved.