From different books I've read, some historical, some based on those time periods - but not historical.....the female age of marriage was anytime after she started her periods because then she was considered a woman because she was capable of providing a child.
Since the average life span was much shorter back then, if I remember correctly, that would make sense in a shepherding/warrior/slave kind of way.
The *average* female starts her menstrual cycle anywhere from 11-13 nowadays. At that time, because of the hard lives in the desert, I would assume children would mature mentally faster. Physically, probably about the same.
So a *girl* would become a *woman* around the age of 12 making her of marriage material. I don't believe there was any actual law saying that she couldn't be given in marriage a tad earlier either. It wasn't her choice anyway - but that of her father's.
I believe some Mormon men still marry very young girls - on a tv program I watched, a man's 5th wife was 15. Even at the turn of the century in the usa, it wasn't uncommon for a girl of 15/16 to get married.
So, it doesn't seem unreasonable that the dual words of virgin women/virgin girls was used in the biblical account.
Now as to how the male soldiers *knew* without a doubt that a girl was a virgin - that would take manual, most likely digital, insertion of fingers to do so by the male soldiers. Then I guess if they found that the girl didn't have her virginity (can't remember the proper name)intact physically, they most likely either stabbed her or cut her head off.
If a girl was taken off as a slave, particularily before the Mosaic Law was written down, it was pretty much whatever the owner wanted to do - the owner could do. Remember the concubine that was raped by the men of one tribe till the point she died? She came home to her owner, and died on his doorstop. He was so enraged that he cut her up in pieces and sent a piece of her to each tribe.
So........it can't be proven that the virgin girls were taken so that men could have sex with them. But it was probable, and it was probable that they worked those girls to the bone because they could. I'm sure some masters were fair with their slaves, especially if the slaves were good, intelligent, and pretty.
Guess if the girl was dumb, ugly, and had a bad attitude, her days could be severely cut short - literally. Well, unless the owner wanted to exclusively for sex and babies. If she literally delivered well, she might live a slave's life.
waiting