What do we know about the gender of nephilim?

Question

Is there any reference to the gender of the nephilim in the Bible?

From what I understand they have been created by sons of God with the women of men (Genesis 6:4 ESV):

The Nephilim^a were on the earth in those days, and also afterward, when the sons of God came in to the daughters of man and they bore children to them. These were the mighty men who were of old, the men of renown.
_{^a Or giants}

But were they only men or were there also women giants? If they were only men how could this be explained? Were the Sons of God capable of choosing the sex of their offspring?

Answer 1

Simply because the text is focusing on the men of the Nephilim does not suggest there were no women of the Nephilim. You see this a great deal in the OT. For example, in Deuteronomy 16, the Lord commanded,

“Three times in a year all your males shall appear before the LORD your God in the place which He chooses, at the Feast of Unleavened Bread and at the Feast of Weeks and at the Feast of Booths, and they shall not appear before the LORD empty-handed. 17Every man shall give as he is able, according to the blessing of the LORD your God which He has given you."

Though it was commanded for the men to attend these feast days, this did not mean these feast days were exclusive to the men. We know this not only because the Passover was celebrated by the entire family unit but also because in all three of the festivals, Israel was commanded to include the orphans and the widows in the festivities of the feasts as well as the Levites and the strangers who were among them, and here, gender is unspecified.

Answer 2

The "nephilim" are clearly male, the word is a BH masculine plural, all the attributes and pronouns ("giborim" "heima") are masculine plural. Their breeding habits are not discussed here or in Numbers 13:33, the only other place the word appears. The notion that they are giants is from the LXX where the word is "gigantes." The Hebrew word looks as though it comes from NPL which means to fall (and related meanings).