You have a new-age Bible there, friend. The Catholic Douay Rheims Bible, a word-for-word English translation of the Latin Vulgate, (the official Bible of the Church for 1,600 years), says it this way:
"I will put enmities between thee and the woman, and thy seed and her seed: she shall crush thy head, and thou shalt lie in wait for her heel."
As you can see the newer "bibles", even the newer, allegedly "Catholic" bibles, keep changing the translation in error. The Church has faithfully and perpetually taught through the ages that it is the Virgin Mary who is referenced in this Genesis verse. Of course Mary crushes the serpent's head through the power of Jesus Christ, as an instrument, just as she was the chosen instrument of which Our Saviour came into the world through.
In Revelation 12 'she' and 'her seed' appears again, clearly as a "woman" and the mother of our Savior, 'her seed' being the followers of Christ.
1 "And a great sign appeared in heaven: A woman clothed with the sun, and the moon under her feet, and on her head a crown of twelve stars: 2 And being with child, she cried travailing in birth, and was in pain to be delivered. 3 And there was seen another sign in heaven: and behold a great red dragon, having seven heads, and ten horns: and on his head seven diadems: 4 And his tail drew the third part of the stars of heaven, and cast them to the earth: and the dragon stood before the woman who was ready to be delivered; that, when she should be delivered, he might devour her son. 5 And she, (note: the Virgin Mary), brought forth a man child, who was to rule all nations with an iron rod: and her son was taken up to God, and to his throne."
6 "And the woman fled into the wilderness, where she had a place prepared by God, that there they should feed her a thousand two hundred sixty days. 7 And there was a great battle in heaven, Michael and his angels fought with the dragon, and the dragon fought and his angels: 8 And they prevailed not, neither was their place found any more in heaven. 9 And that great dragon was cast out, -------".
11 "--------- 13 And when the dragon saw that he was cast unto the earth, he persecuted the woman, who brought forth the man child: 14 And there were given to the woman two wings of a great eagle, that she might fly into the desert unto her place, where she is nourished for a time and times, and half a time, from the face of the serpent. 15 And the serpent cast out of his mouth after the woman, water as it were a river; that he might cause her to be carried away by the river."
16 "And the earth helped the woman, and the earth opened her mouth, and swallowed up the river, which the dragon cast out of his mouth. 17 And the dragon was angry against the woman: AND WENT TO MAKE WAR WITH HER SEED, who keep the commandments of God, and have the testimony of Jesus Christ. ---------"
3:15 And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.The previous translation I quoted changed "it" to "he" because I presume they didn't like calling Christ "it", even though "it" refers to the term "seed".
This is where I see the problem with the interpretation of the term "she" being Mary: in what way did Satan ever bruise, or lie in wait for, the heel of Mary?