She was just the mother of the son of God at that time. No need for veneration or knowledge of her after the mention of her in Acts 1 where she is listed along with her other
sons, the brothers of our Lord, who became cousins to aline with the claim of her being a perpetual virgin.
It was 300 plus years later when she became the mother of God that all the special attributes and veneration became necessary. By then, nobody could remember where she ended her days and/or what happened to her remains.
All is not lost. With no relics, we can claim she was assumed into heaven. Our religion is not based on scripture alone as we proudly boast. Jesus is the head of our church but He gave Peter and his successors the right to be the teaching authority. We call that the magisterium. Anything they decide is as if God said it. For all practical purpose, it is our God.
Hope this is of help, BVB
**brothers of our Lord,**
The term “brothers of the Lord” was used for cousins. Mary had no other children.
‘cut to the chase’ comes to mind.