ISTR (and am resisting the call to Wiki it), bras were invented at about the time that Rational Dress was coming into fuller acceptance, i.e. the earlier parts of the 1900s, and were originally two handkerchiefs and some connecting material in order to avoid the whalebone corsets and other restrictive bodice-like 'foundation garments'.
But there were apparent precursors in prior ages (not obviously inspiring the above emergence) including solid evidence for breast-banding (for less pain during active pursuits, rather than for 'drag king' binding down of awkward lumps'n'bumps of femininity) amongst Roman women. Essentially a minimalist 'boob-tube' worn (together with nether garments) in stark contrast to the stari naked Greek men of sport.
There might well be a number of classes of female-UB clothing practical to include. Some, though surely not all, of bustiers, bodices, kirtles, dirndls (had to check that spelling!) and various forms of (proto-?)corsetry. Being no real expert in clothing terminology, and vaguer yet about female garb (to protest only about the right amount, not too much) I wouldn't know the difference between half of them anyway.
But the "two hankies" thing I'm sure I heard of in the '70s (may be fashionably wrong, as of the time, and debunked since). The question to ask is whether dwarven mammary tissue is (outside of such scant evidence gleaned from the Raws) as prominent and sometimes precipitous as we expect to see in Earthly hu(wo)mans, or not. Other than bearing the children, sex and gender issues tend not to be obviously important in their lives. Perhaps this extends to upper-torso (or whatever domain applies) physiology.