Prior to the establishment of the modern military regimental system and modern military supply, which largely came into its own during the Enlightenment, armies were followed by trains of people who were not soldiers, but performed various tasks for their armies. Collectively, these were called "camp followers". That phrase has a nasty connotation of prostitution because among the camp followers there would frequently be prostitutes; however, they were far from the only people who followed the camp. An army, in particular, would require armorers, cooks, leatherworkers, people who forage for food either from the local area, as well as entertainers of various sorts, such as bards, minstrils, etc. as well as the infamous prostitutes. These followers could be of either sex, and have any relation to the soldiers, including being just people from the local area who might make some coin cooking for the army or even just some adventure travelling with them.
While actual female soldiers in the day were rare, it was not at all uncommon in period for a soldier's wife to accompany him off (and sometimes on) the battlefield. This is a perfectly natural for her: she loves him, wants to be with him, and wants to look out for him as she can, so perhaps she cooks for him and his troop, or forages, or helps him loot the area after the battle is won. She would be armed, if lightly, because travelling in such a situation would be potentially dangerous. If he fell in battle, it was even possible for her to fight in his stead.
In a game like most nation-builder real-time-strategy games from Age of Empires onward, there is a distinct gender bias in the characters in the game. Generally, only the citizens and perhaps a few support units can be both male and female; all of the soldiers are male. That the units that are male should be is of course realistic; even among the Elves and the Woses of Arda I don't see the average soldier being just as likely one sex as the other. However, I do see some of the races having the wives of the soldiers being much more caring and much more dedicated to their husbands than even real-world humans. In fact, even among Men in Arda I see some groups (the Edain) having their females more likely to follow their loved ones (think about Morwen, and Huor's wife).
It seems to me therefore that some of the races should have follower spouses of the soldiers. So, here is how I would suggest it: every time a soldier is produced of a race where the females are particularly devoted to their spouses, a wife for that soldier is produced as well. She can't easily be controlled (though she probably can be given a "conceal yourself" order so that she doesn't tip off the enemy where your army is). Instead, she would follow her husband around, provide logistics bonuses to him as long as she is alive, and be a functional but not necessarily great combatant if she should get into trouble herself. Of course the soldier would cost more in the first place, since you get two units for the price of one. I would generally say that the Elves, the Edain (and some of their descendents) the Woses, and possibly the Hobbits, should get this feature. Dwarven females are sufficiently similar to the males that if you dressed them up in armor you couldn't tell them apart (and I get the feeling the Dwarves did this), not to mention of course that there are only half as many of them as Dwarven males. Easterlings, Haradrim, and Orcs don't get this feature because their marraiges are more often loveless.

