Between the passage already discussed above in Gen 3:15 and the one mentioning the conception and birth of Seth in Genesis 4:25, there are a couple of similarities in words used.
Firstly, in Gen 4:25, the word ‘appointed’ (Strongs Hebrew number 7896) meaning ‘to place’, ‘to put’ or ‘to set’ and used in a wide variety of situations and contexts is the same word used in Gen 3:15 and translated by the word ‘put’ as in
‘I will put enmity between your seed and her seed’
It should also be pointed out that Seth was called so because of the closeness of that name (if ‘names’ existed at that time! It would be more reasonable to think that each name given to a new birth was ‘new’) to the Hebrew word for ‘put’.
Secondly, in Gen 4:25, the word ‘child’ (Strongs Hebrew number 2233) - meaning more correctly ‘seed’ or ‘offspring’ - is the same one translated by the RSV as ‘seed’ which twice occurs in Gen 3:15.
Gen 3:15 and 4:25 therefore become possible parallel passages, the former stating that
‘hostility will be put/set between the serpent’s seed and the woman’s’
and the latter stating that Seth (‘put/set’) had been ‘put/set’ on the earth as the seed to replace Abel’s line. Seth’s conception was therefore ‘appointed’ by God in Eve’s eyes and so the RSV translates the Hebrew word in Gen 4:25.
Eve’s statement in Gen 4:25 is therefore a confession of faith that she believed it was to be through Abel that God was to bring her ‘seed’ to redeem mankind and to overthrow the serpent but that, because of what had happened between Abel and Cain, God had allowed her to conceive another child to replace the Messianic line. God doesn’t state that this was so, even though this was the line that He chose, through Noah, to Abraham and beyond.
It’s worthy of note that it wasn’t until Adam (and, therefore, Eve) was a hundred and thirty years old that Seth was born. It seems possible that the first son that Eve conceived after Abel’s murder was Seth and that, in him, she saw the replacement for the hope of mankind.
If this is so, then Eve correctly prophesied the first patriarchal line of the Messiah and she should be considered as the first prophetess in the Bible.