Genesis 3:13-16
13 And the LORD God said to the woman, “What is this you have done?” The woman said, “The serpent deceived me, and I ate.” 14 So the LORD God said to the serpent: “ Because you have done this, You are cursed more than all cattle, And more than every beast of the field; On your belly you shall go, And you shall eat dust All the days of your life. 15 And 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.” 16 To the woman He said: “I will greatly multiply your sorrow and your conception; In pain you shall bring forth children; Your desire shall be for your husband, And he shall rule over you.”
Contextually, the "woman" is Eve. Contextually, he is speaking of the "Seed" of Eve. Certainly I agree that the "Seed" is the first Messianic prophecy. However, it does not follow that the "woman" is a Mary prophecy. The fact is, EVERY SINGLE PERSON who has ever lived (exceptement Adam) is the "seed" of Eve.
Okay, then WHAT is the emnity?
One other thing...
Throughout the entire passage, the woman serves as a representative for all women. The consequences of her decision - pain in childbirth, being ruled over by her husband - were extended to all women. Contextually, this same representative position of Eve should be accounted for in the entire passage. The woman referred to in verse 15 is the same woman as in the rest of the passage, serving in the same representative capacity.
Ergo, the woman must be Eve, not Mary.