Rather interesting article from - What Kind of Armour Did Medieval Women Really Wear:
We know that skimpy armor that shows off a woman's cleavage is rather impractical for combat and that sculpted "boob plate" armor can be a hazard to your health, but on occasions that women did don armor in medieval Europe, what kind of armor did they actually wear? And is shapely, feminine armor a modern convention, or does it have some roots in the Middle Ages?
Even if they aren't necessarily historically accurate, depictions of armor worn by men in European historical fictions or European-inspired fantasies tend to have at least some basis in fact, whereas women's armor is often depicted in a more fantastical manner. There are, of course, the infamous body-bearing suits of armor with scale mail bras and chain mail loin clothes that seem to scream, "Please, stab me in my fleshy stomach!" And then there is the overly sculpted boob-plate breastplate for suits of plate mail, which gives fictional woman warriors the appearance of femininity, but places a rather dangerous metal protrusion right at the wearer's sternum.