In The Return of the King, Appendix A, there's this quote about female dwarves:
Dís was the daughter of Thrain II. She is the only dwarf-woman named in these histories. It was said by Gimli that there are few dwarf-women, probably no more than a third of the whole population. They seldom walk abroad except at great need. They are in voice and appearance, and in garb if they must go on a journey, so like to the dwarf-men that the eyes and ears of other peoples cannot tell them apart.
Do the females have beards too, as 'the eyes and ears of other peoples cannot tell them apart'?