Bikini armor is just as realistic as any other kind of female armor because historically speaking, there were no female soldiers to wear armor.
One might also argue that a chastity belt was the most common piece of 'armor' worn by women, making bikini armor the most realistic.
While most armours would have been made for men, there were instances where women would have historically speaking, been soldiers and/or worn armour. The Roman emperor Severus banned women from participating is gladiator games after a couple hundred years of it going on. Enough artifact sculptures laying around to prove they did fight in the arena too. There were female Scythian nomads also buried with their weapons and armour alongside the men. During the American Civil War it was not unheard of for women to pretend to be young men so they could join and fight (see the Declaration of Independence for names, there are women, who were soldiers, albeit not wearing your medieval-fantasy style armour). One of the old Chinese Dynasties was shook up by a woman after her husband and their rebels were seized and likely tortured to death. She was definitely a soldier with light armour who rode horseback. Joan of Arc never fought, but also wore armour. Lots of historical examples out there where women were indeed soldiers and also wore armour.
It doesn't change the fact that bikini armour is unrealistic though.
Everyone knows that the queen had a custom suit of ceremonial armor and you can always find some women willing to perform extreme entertainment. When your counter-argument relies on such examples, it isn't very good.
Yet you said ". . . no female soldiers to wear armor." That implies an absolute. I also mentioned examples of females who would have been soldiers before the modern era. The Scythians weren't entertainment, they defended themselves. Neither were the repressed Chinese, and that was a soldiering example. American women fought in the Civil War. You don't understand history. The Roman case isn't even a matter of just "find women," plenty of them were forced to as any other slave.
Also, I gave no ceremonial examples. You gave the ceremonial example, which makes it evident that you have no clue what you are talking about as you just proved my point. If you want to crawl into the territory of realism, then most video-games have terrible representations of how combat with armour and the weapons used would actually work. Point of fact, not all armour even has to be plate. In fact, most armour would NOT have been plate if you take the sheer amount of different armour out there. More men protected by leather in history than plating any day if you want that scale to go off of.
It appears that you mistook some colloquial language in a funny forum post for a legal document. Find an example that is more than half of one percent valid before climbing that high horse.
"A woman wore a leather vest into battle one time" isn't a great example of female plate armor. Or are you arguing that men in games should have full plate and women should cap out at leather brigandines? Why do you care so much about this?
You are clearly brain-washed by video-games and movie/tv interpretations that woman would have "special" female armour, as in boob-plate or something. You're missing the point and couldn't be further from the truth. There is no special "female armour" because females have always just worn the same armour a male would wear. Armour is armour. Not all men fit into the same armour and that is why there have always been different sizes and "custom fits" if you didn't want cookie-cutter armour seeing as there are different sizes, styles, etc. Try putting a typical Navy Seal in a traditional Roman centurian style and he likely wouldn't get the chest-piece on by virtue of Romans being shorter and smaller than a modern soldier (yet that armour was still "made" for a man) but a modern woman would likely fit just due to size. If you remade it however, you could in fact get it on the Navy Seal. Joan of Arc's heavy metal plating was extremely typical of what a man would wear, (albeit tailored to her just as a wealthy noble may have the same type of metal armour tailored to himself). A barrel-chested man will require a chest-piece that allows for more chest space than an average woman would require for the same chest-piece. If you think breasts might require that modification too then news for you, breasts flatten easily and women have less chest mass than men, which is why typical armour works fine on both sexes. Kevlar vests come in different sizes for a reason, but it's still a kevlar vest. Most places you just pick your size (S, M, L); man or woman. While female-tailored kevlar vests exist, that luxury isn't the reality for most departments and most women wear the same type of vest as a man if they are a police officer.
The most
realistic armour for a woman is wearing just any regular armour that fits her person, just as is the case of any man. That's why there is no such thing as this special female armour. It doesn't exist. A human form is a human form.