The direct answer is, God's woman is God's heavenly organization, or family, of spirit creatures. This is why it can be the only answer:
Genesis 3:15 says:
"And I will put enmity between you and the woman and between your offspring and her offspring. He will crush your head, and you will strike him in the heel."
The woman is not Eve, because by sinning she put herself and most of humanity on Satan's side, not at enmity with him. Satan the Devil, the deceiver, was speaking behind the serpent. She chose to believe Satan rather than her Creator, and wanted something that the serpent implied was good, but was being kept from her by God's command not to eat of the fruit. Also, by contradicting God by saying that if she ate of the fruit she will not die, when God said that she would, Satan was calling God a liar.
Usually, when a prophecy is spoken in the Bible, we also read later how it was fulfilled, or at least more information about its fulfillment is mentioned later. So that is what we have here.
Genesis 3:15 is part of the first prophecy in the Bible. It would be useful to find out who the seed, or offspring, is, because then it would be easier to identify the mother of that offspring. The next time a seed and a promise was mentioned was in connection with Abraham. God said that by means of this seed or offspring all the nations will be blessed. In Genesis 18:20 God said:
"And by means of your offspring all nations of the earth will obtain a blessing for themselves because you have listened to my voice.’”
ALL nations of the earth. Who is this seed through whom ALL NATIONS OF THE EARTH will obtain a blessing?
Paul under the inspiration of God, tells us directly:
Galatians 3:16 Now the promises were spoken to Abraham and to his offspring. It does not say, “and to your descendants,” in the sense of many. Rather, it says, “and to your offspring,” in the sense of one, who is Christ.
This verse was translated this way because the literal translation "seed" can be singular or plural, while "descendants" is plural, and "offspring" can be singular. In this verse, it becomes clear that the Christ is the primary fulfillment of the prophecy in Genesis 3:15.
Jesus descended through Mary from Abraham, and so the nation of Israel who was Abraham's descendants were also the earthly part of God's woman because of the Law Covenant that he made with Israel. (Isaiah 54:5-6). But Jesus did not come only from Mary, which shows that Mary is also NOT the woman in Genesis 3:15. We read where Christ came from, from his own expression:
John 6:51 "I am the living bread that came down from heaven. If anyone eats of this bread he will live forever; and for a fact, the bread that I will give is my flesh in behalf of the life of the world.”
John 17:5 So now, Father, glorify me at your side with the glory that I had alongside you before the world was.
So Jesus Christ originally came from heaven, as the firstborn of all creation (Colossians 1:15). Through faith in Jesus and his ransom sacrifice, people of ALL NATIONS can have the everlasting life. (John 3:16) This is the blessing that God purposed and expressed in the Edenic promise.
Also, because the seed - plural - of Abraham will also be blessed, Paul identified who they are, as well:
Galatians 3:29 "Moreover, if you belong to Christ, you are really Abraham’s offspring, heirs with reference to a promise."
Those who will be kings and priests over the earth with Jesus, as his bride in heaven, will also be Abraham's offspring. (Revelation 5:9-10; Revelation 14:1-3) These are the seed or offspring of Abraham.
So, God's woman from whom Jesus was born is his heavenly organization of spirit creatures who are in subjection to her husband, Jehovah God. The scriptures also call her "Jerusalem above" (Galatians 4:26) When in heaven, Jesus did have a role with his Father in creating those who make up this heavenly organization, but his role as Christ began when he left heaven to become a human on earth.
Jesus Christ came to the earth from heaven as the offspring or seed of God's woman in order to fulfill the promise given by his Father to Adam and Eve in Eden that the seed of the woman will crush Satan's head, and also to faithful Abraham to whom he promised that all nations will be blessed through his seed, or descendants.
Jesus, the only begotten son of God, is the one who "will bring to nothing the one having the means to cause death, that is the Devil", thus fulfilling the prophecy in Genesis 3:15. (Hebrews 2:14) Those who are selected by the Father to become Jesus' heavenly bride will also be Abraham's seed in heaven.