We saw Gimli discussing dwarf women with Eowyn in the The Two Towers:
Gimli: It's true you don't see many dwarf women. And in fact, they are so alike in voice and appearance, that they are often mistaken for dwarf men.
Aragorn: [whispering] It's the beards.
Gimli: And this in turn has given rise to the belief that there are no dwarf women, and that dwarves just spring out of holes in the ground!
Gimli: Which is, of course, ridiculous.
Is the theory that dwarf women look like dwarf men limited to the works of Tolkien?