Either Eve was not aware where her "Cain" came from or the serpents initial encounter with Eve brought forth from that point when the serpent was Eve's desire speaking to her to be confused with the Lord. Either way corinthians 15 lays it all out. Continue down it shows what comes next... to raise Abel as immortal and Cain incorruptible. Death(spiritually) is then defeated.
There is a seed of Satan but it doesn't come from sexual intercourse with Eve, it comes from mental intercourse with here. According to the bible, words are seed. The words the serpent spoke to Eve in the garden seeded lust in Eve's mind. Eve believing the words of the serpent conceived lust in her mind, the conceived lust brought forth sin and the sin brought forth death.
Jas 1:14 But every man is tempted, when he is drawn away of his own lust, and enticed.
Jas 1:15 Then when lust hath conceived, it bringeth forth sin: and sin, when it is finished, bringeth forth death.
In the KJV the serpent spoke exactly 46 words to Eve. The number 46 points to human have 46 chromosomes that hold our DNA. We also see the number 46 associated with the human body in the New Testament.
Joh 2:19 Jesus answered and said unto them, Destroy this temple, and in three days I will raise it up.
Joh 2:20 Then said the Jews, Forty and six years was this temple in building, and wilt thou rear it up in three days?
Th KJV is an awesome... it has God's signature all over it!