Genesis 4:22 "And the sister of Tubal-Cain was Naaman."The mention of one female that was not a wife and she's not even identified as a daughter.
Genesis 5:4, 7, 10, 13, 16, 19, 22, 26 and 30 "After he begot Seth, the days of Adam were eight hundred years; and he had sons and daughters...7 After he begot Enosh, Seth lived eight hundred and seven years, and had sons and daughters...10 After he begot Cainan, Enosh lived eight hundred and fifteen years, and had sons and daughters...13 After he begot Mahalalel, Cainan lived eight hundred and forty years, and had sons and daughters...16 After he begot Jared, Mahalalel lived eight hundred and thirty years, and had sons and daughters...19 After he begot Enoch, Jared lived eight hundred years, and had sons and daughters...22 After he begot Methuselah, Enoch walked with God three hundred years, and had sons and daughters...26 After he begot Lamech, Methuselah lived seven hundred and eighty-two years, and had sons and daughters...30 After he begot Noah, Lamech lived five hundred and ninety-five years, and had sons and daughters.
In the context of the genealogies we have one mention of a female that is not a wife and not even mentioned as a daughter. With 9 verses saying, sons and daughters were born to the mentioned dependent of Adam. In that context Genesis
In the context of Genesis 4:17-24 who is are the ones that were not many and have no mention of daughters being born to them? Cain. In the Context of Genesis 5:1-32 who have mention of many sons and daughter being born to them? Adam, because his genealogy was multiplying on the face of the earth and had many daughter born to his genealogy, in the context, with Cain not so much, with again not even the mention of a daughter being born to them, in the context. This is why Genesis 6:1 starts out with, "Now it came to pass" when and daughters. In that context set up in Genesis 4:17-5:32, who is it talking about that were not multiplying or having daughters on the face of the earth? Cain, identified as "men" and now they were multiplying and having daughters on the face of the earth.
6:1 "Now it came to pass, when "men" began to multiply on the face of the earth, and daughters were born to them,"
The judgement Genesis 6:3 “And the Lord said, “My Spirit shall not strive with "man" forever, for he is indeed flesh; yet his days shall be one hundred and twenty years.” It's not talking about men that are now having daughters and multiplying on the face of the earth. The LORD is now talking about both genealogies and that He will strive (time to repent) with him (man) 120 years.
Genesis 6:5 "Then the Lord saw that the wickedness of man was great in the earth, and that every intent of the thoughts of his heart was only evil continually." Is the LORD blind or is He playing favorites, why is He judging all of mankind, if 6:4 are fallen angels and those children are half angel and half human, He's not because they are not. They are mankind that has become wicked and every intent of thought in their hearts were only evil continually.
Why did the LORD judge all mankind for the deeds of some fallen angels and some provocative women, He did not. He judge what man had become. The sons of God is not that they were in special relationship with the LORD, it's that Adam's genealogy is being identified with Adam as he was identified in Luke 3:38 "Adam, the son of God", the term "men" is used for Cain to separate his genealogy from Adam's. Them when the judgment was rendered it was on "man" no separation, it is on all men.