This is a case in which more than one translation and interpretation of a scriptural passage is valid.
In the broadest sense, the Church as a whole is Eve’s seed, standing in missionary opposition to the serpent’s (i.e., the devil’s) seed/demonic confreres (Rom. 16:20; Rev. 12:17). In addition, the Catholic Church has long seen Eve’s seed as referring to the Messiah, Jesus Christ, who conquers over sin, Satan and death through his one Sacrifice of Calvary (Heb. 2:14; 1 John 3:8).
In this light, we see that the RSV Catholic Edition and the NAB Revised Edition translate Genesis 3:15 similarly to traditional Protestant translations:
“I will put enmity between you and the woman, and between your seed and her seed; he shall bruise your head, and you shall bruise his heel” (RSVCE).
“I will put enmity between you and the woman, and between your offspring and hers; They will strike at your head, while you strike at their heel” (NABRE).
These represent a more grammatically precise translation.
However, the Church Fathers and the Douay Rheims translation reflect a Mariological interpretation, in which Mary is understood as the “New Eve,” bearing the Redeemer of the world via her “Fiat/yes” (Luke 1: 37), whereas the first Eve failed to trust and obey God:
“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.”
This rendering of Genesis 3:15, with the support of so many of the early Church Fathers, illustrates the exalted status the Blessed Mother had in the early Church.
For more on Mary as the “Ark of the New Covenant,” please see our article by Patrick Madrid.