First, keep in mind that I'm not a theologian, prophet, or anything like that. That's why I's inspired to use Amos, who from the Bible, likewise, didn't have any "formal training."

There are some that argue "angels are gender-less." But what proof is there for that? Here is one article. "The fact that there is no marriage among angels does not necessarily mean there is no gender and no procreation." I would agree with that. It is said that the "sons of God" took women, and had children with them. After coming across 1 Enoch (not canon in all versions of the bible), it specifically states that these "sons of God"  are angels (later sometimes referred to as fallen angels and/or demons).

So, since they can obviously reproduce with human women, it must be concluded that angels do have genders. "But the bible doesn't refer to any female angels." I'll get to that, shortly. It's said "let us create man in our image." While Adam was the first, Eve was created, too. Adam shouldn't be alone, and needed a helper. If there were no female angels, then why was his helper a female, and not another male? This tells me that there are male and female angels in Heaven. I also can't help but wonder if any of the female angels came, and decided to be with "mortal men."

Here, there is a reference to the possibility. While they are not specifically stated to be angels, there are many times where there are "agents of God carrying out His work," but they are not specifically stated as being angels, in all cases (many assume so).

There are also (and this is going more out there, outside of even "non-canon books") some articles, talking about female archangels. There are some who think that Uriel is Ariel, and that "male dominate thinking in the early churches may have rendered some female names to male versions." That, isn't the scope of this posting. But, given what I've covered so far, I believe that there are male and female (arch) angels, with sons and daughters of God. If there wasn't, we, who are supposed to be in "Our Image" would exist as only one gender, or "gender-less." Clearly, not the case.

Take it how you will.