I figured out one possible reason we've never seen a female Dwarf. There are none.
Dwarves marry human women. Their children are either full-blown Dwarves (the males), or normal human women (the females), because the Dwarven gene is absolutely dominant, but only manifests itself in men.

This came to me a week or two ago, and I had to share it .
Do you believe in Dwarven Women?

One of my favorite parts of The Hobbit was the fact that we got to see dwarven women.

That is a really cool idea, Kelcin. I could list several reasons how this likely isn't what Tolkien had in mind, but I am quite fascinated with the idea of a one-gender race now!

And Arianna: We did? Cool.

I feel like I missed that. But, I probably wouldn't have noticed.

Dwarf women have beards.

Yeah, their beards and hair were like the dwarven men, but their faces were women faces. They looked a lot like the men.

Although the dwarf women had little beards only.

That...is a brilliant idea. I had never thought of that before.

Very intriguing, and it is an explanation.

Yes, we saw some dwarf-women in the Hobbit. It was a bit difficult to spot them though.

How interesting.

Yes, I noticed that in the Hobbit as well!

I like the idea of Dwarf-women though, although this is an interesting concept.

Difficult to notice? That was actually one of the first things I saw-okay, maybe not first, but still.

This is actually a really good idea.

I used/am using a variant of this in my fantasy story (way before I saw this post). I have a race of shape shifters that can only shift into wolves (long story). The shifters are only women though. If their husband is a wolf, their male children would be full wolves and the females would be shape shifters as well. If their husband was a human, the sons would be human and the daughters would be shapeshifters.

Would this actually be plausible? What would be the downsides?

And if I should just reask this in its own thread, I apologize and would be happy to rectify my mistake immediately.

I think it would be plausible – it's a cool idea.

The downside I can think of is if the race was shunned by the other races, their numbers would diminish rapidly and there would be the risk of extinction, since few people would want to marry one. And they would already be a slower growing race when it comes to population, even if not shunned, because about half of the children would be male and thence not shapeshifters.

That's a good point...

Immortality would at least allow the numbers to stay the same, wouldn't it?

Mm, yes, that would help. Depends on how immortal they are – like, whether or not they are able to be killed outright, and whether they can die of sickness – but even if there are some ways for them to die, not dying of age alone would help with preventing them from becoming extinct. Then the only difficulty would be that they would not increase in numbers as fast as the other races would.

Not necessarily a bad thing, though, it could add some interesting conundrums and such to your world building.

I call it 'functionally immortal', and i think I heard that term somewhere, but can't remember where. It means that they can't die of sickness, they don't age past a certain point, and they're incredibly hard to kill and can come back-with the right care-from terrible injuries. They can still be killed, but it's incredibly hard. I might invnt a sickness that only affects them at some point, but that's up in the air...

It gets really intersting when the humans, who fear anything that is not of their own race, label the immortals as cursed and try to kill them all-and nearly succeed-so the immortals have to restart their lives every twenty years or so...

Cool! That sounds like it'll work.

Thanks! I hope it does.

Immortality works well for the lazy-they don't have to think up more characters...

Never thought of that.

*grins*

I'm not exactly doing well in my fight against procrastination...I always figure I'll do something about it tomorrow.

I really adore this idea! Its super clever and I'd love to see how it would effect the dwarves culture. Would they see them selves as a superior race?

I've been working with dwarves in my story and my idea for females leaned more towards the idea of "Valkyries." Of course there is some variation. I just imagined them being good warriors, beautiful, and very serious figures. So all the mythology of the Valkyries would just be from seeing a dwarf woman in battle.

Wow! This is a really interesting consideration! It's something I have wondered as well...
I will have to think about it some more and see if there are any other possible answers.