Well, MHGinTN, this is moving quickly toward the pointless. You specifically declared that Mary was not - NOT - genetically the mother of our Lord. Now, you are saying that maybe she was, and that we can’t know.
You are also redefining the term “mother of.” You seem comfortable saying that He was conceived within her and that she gave birth to Him. What you seem to be avoiding is calling her His mother, which the Bible has no hesitation in doing so, e.g., Luke 2:33, in which context her relationship to Him is strikingly noted as different than that of Joseph to Him.
I find your insistence that the Scripture would need to say explicitly that Jesus is of Mary’s ovum before one could say that she is His biological, genetic mother to be very troubling. Words have a meaning. In the given contexts where Mary’s motherhood of Jesus is noted in the Holy Scriptures there is no call whatever to take the word mother in any metaphorical manner, which is what you are saying whether you agree or not.
Since you insist upon Mary's ovum being at least half of the chromosome complement for Jesus, perhaps you will explain for me how it is that Adam's original sin is passed to any other human descendant of Adam and why Mary would needs be sinless, genetically. Because you are asserting that somehow Mary's genetic contribution had to be sinless, thus you have apparently some means by which to explain the passing of Adam's sin nature to his desecendants such that this passing may be 'cured' with Mary?
What I am seeking to sort out for you is that unless there is some biological/genetic means by which Adam's original sin nature can be passed to Mary (a means which you have yet to point to), then there is no reason she would have to be sinless in gestating Jesus in her womb.
Mary is The Mother of Our Lord Jesus Christ. The Bible declares it and I believe it completely. The Bible does not specify just how she is the Mother of Jesus genetically.
The Bible gives the lineage of Joseph for paternal descendant rights conveyed to Jesus, and the lineage of Mary also, for maternal lineage rights.
Mary is not 'metaphorically' the Mother of Jesus. She bore Him in her body for the nine months of His gestation. She is physically His Mother, just as a woman may be The mother of one conceived in vitro and implanted in her body for the nine months of gestation. I'm sorry that trips you a bit, but there it is. We believe God miraculously conceived Jesus in Mary's womb. That makes her absolutely His Mother.
We do not have any thing further to establish genetic lineage. We do not know How God Did It. The Catholic Church does not know, nor do any other orthodoxies. The Catholic Church wants folks to believe they have the absolute facts on the issue, but they strain at a gnat to make Mary sinless from her mother's womb in order to support their not so specific claims of knowledge. has the Catholic Chruch referred for you just how it is that Adam's original sin is transmitted through the gene pool? If they have, I would like to read that!
As a matter of my personal beliefs, I do not in fact believe that Mary is the genetic Mother of Jesus. I simply do not know how God did it. I do however, most strongly believe that God did IT, conceived Jesus in Mary's womb.
You might want to contemplate the phrase 'conceived in you', because it is entirely possible that The Angel was referring to implantation in Mary's womb, not the union of spermatozoon and ovum conception. My personal belief is that God brought to Mary's womb the already formed embryo-aged Jesus for implantation. God may enter the womb of Mary as easily as Jesus entered the locked and shuttered upper room.