On occasion I have come across the delineation of the Virgin Mary as "Daughter of the Father, Mother of the Son, and Spouse of the Holy Spirit." This makes for a neat package, tying Mary in relationship to each person of the Trinity. The first two roles make perfect sense. Mary is the daughter of the Father, along with all Christian women, and obviously she bore Jesus, the Son of God. Referring to her as spouse of the Holy Spirit, however, poses some potential problems and leaves the door wide open for misunderstanding. The use of another title for Mary, "Bride of Christ", has similar issues. Due to the Church being understood as the Bride of Christ, and Mary being a unique and most exemplary member who often symbolizes "Mother Church", Mary herself is sometimes referred to as the spiritual bride of Jesus. Again, this blurs some obvious lines, and I feel that this designation is perhaps better left out of any reference to His mother.
First I would like to revisit the subject of gender in relation to conceptualizing the nature of God. God is pure spirit, neither male nor female in the way that we human beings are. He is not an androgynous being, either. Rather, both the masculine and feminine principles are contained within Him, as we men and women are made in His image. God is characterized biblically in both fatherly and motherly terms, yet it is the Father metaphor that is specifically used to denote the first person of the Trinity, and it is the name, Abba, Father that Jesus uses himself. I think of the first person of the Trinity as primarily a father. The Father in this sense is transcendent, while the Mother aspect is more immanent, even hidden, one might say. It is Mary through whom God reveals His maternal face, which is one reason why devotion to Mary as spiritual Mother is important.
God's masculine presence in human form is seen through Jesus, the Son, who is both fully human and fully divine, and is the son of Mary, a completely human creature. It was through the Holy Spirit, the third person of the Trinity, who proceeds from the Father and the Son, and by the power of the Most High, that Jesus incarnated as a man. Mary was filled completely with the Holy Spirit and, in my estimation, received the indwelling of Holy Wisdom/Sophia, a feminine emanation of the Holy Spirit.
This process of the Incarnation does not indicate that Mary experienced the sacrament of marriage with the Holy Spirit, and it also does not imply any sexual activity. When people use the title "Spouse of the Holy Spirit" for Mary, they are expressing a spiritual union that occurred; still, it seems likely that this designation runs the risk of being confusing and, ultimately, theologically questionable.
I have previously written that I understand the Holy Spirit, due to the way the Spirit is described and functions in the Bible, as a primarily feminine person, especially in light of the feminine Hebrew name for the Spirit, Ruah. She is also often depicted as a mother bird or a dove, which is universally a feminine, spiritual symbol. But how could the Holy Spirit have formed a union with Mary that resulted in the Incarnation of Jesus in her womb if the Spirit is feminine? As I have previously stated, I read the verse in Luke as pointing to the working of the feminine Spirit coming upon Mary, and the masculine power of the Most High overshadowing her. Both principles were at work in this mystery. Because of our limitations in using the human language of gender when speaking of God, who is pure spirit, it is difficult to understand how the Holy Spirit could be understood in feminine terms. But this was a spiritual phenomenon, not a human marriage of opposite sexes.
But what of the Holy Spirit proceeding from the Father and Son? This would seem to indicate that the Spirit could not be mother. Again, gender as we understand it in human terms is not the same in revelation of the divine nature of God. And I do not argue that the Holy Spirit is necessarily the Mother aspect of God, although I think this is somehow mystically possible under consideration of the creation of Adam and Eve. Eve was created from the rib of Adam, so that she became "flesh of his flesh, and bone of his bone." Eve, the "mother of all the living", proceeded from Adam, who was created by God the Father. Created last, she was indeed the pinnacle of God's work, so in a mystical sense, was at the same time first and last among creation.
Even if one completely disagrees with me on this point of the femininity of the Holy Spirit, there is another, compelling reason to avoid speaking of Mary as Spouse of the Holy Spirit in a literal way; that is, the fact that Mary had a human husband, and his name was Joseph! Joseph's role cannot be ignored, even if he did not have a sexual relationship with Mary. Under Jewish law this couple was married, and so Jesus was considered as much a son of Joseph as he would have been if he had been Joseph's biological child. Joseph was descended from the House of David, and therefore so was Jesus, as it had been prophesied of the coming Messiah in the Old Testament.
Joseph protected Mary (and her unborn child) from being stoned to death for alleged adultery. He protected them on the 70-mile, arduous journey through the desert from Nazareth to Bethlehem, and from there to Egypt to escape the murderous wrath of Herod. Joseph went with Mary to find Jesus in Jerusalem, where He had stayed behind in the temple after the Passover feast, and made sure that He returned safely home. Joseph's job as an earthly father to Jesus was an enormous responsibility, and so was his role as husband to Mary. Joseph was seen with Mary at the apparitions of Fatima in Portugal in modern times, and so he has evidently continued to be with Mary in heaven.
Considering all of these factors, I contend that a title such as Channel, or perhaps Mediatrix of the Holy Spirit, rather than Spouse (or Bride of Christ), would be far less confusing and more theologically accurate, and it would not undermine the very important part Joseph played in God's plan for the redemption and salvation of humanity. It also gives married women who are neither virgins nor mothers a more solid role model to look toward in the position of Mary as the wife of Joseph in a completely human, domestic relationship.