If we have a 22 year-old woman taught to use a sword by her father (in a historical fantasy kingdom setting) what would have a been a reasonable age her to start learning (using wooden swords)? In this setting, there is no social norm against woman learning to fight in any capacity. And if my setting is more Western, what would be a minimum reasonable age when she could carry her own real sword?
At the same age as the boys.
This is the problem when you want to do these setups. You have to forget that your character is female. There is literally no difference between a girl’s combat training and a boy’s. It is exactly the same, the expectations are the same, and the part where she’s female is tertiary as best. If you over focus on the fact she’s female (any hint of her being treated differently) in a setting where social norms about women in combat don’t exist will result in you shooting yourself in your own foot.
The minimum age is going to depend on her father, and will depend on her social station, which also depends on the kind of training she receives. This also depends on the sword type in question, whether we’re in the Middle Ages or the Renaissance, and if she’s expected to do anything else along with the sword fighting. For example, if she’s a knight versus a duelist. If her father is a mercenary who needs all hands on deck quickly, or can take his time about deciding when he lets her loose. If she apprentices outside of him, as knights did when they were sent out to serve as pages, then squires before they became full-fledged knights at twenty-one.
The problem here is that this girl’s training will go through several stages with weapons that are, technically, real. All training weapons are real. The wooden sword is a real weapon. The steel training sword which is blunted is also a real weapon. They are just not as immediately dangerous as a live blade, and she will never ever train with a live blade even after she receives one as her graduation present. The graduation present will probably coincide with whatever this setting considers her age of adulthood, which could be anywhere from fourteen to twenty-one depending on her social status. This one is going to depend on her father, and her setting. Her father might give her a real sword to take care of in her early teens which she gets to train with but not use on practice dummies or spar with, to teach her the importance of caring for her weapon. She might be allowed to carry it when traveling as her father’s second, but not use it outside a means of self-defense
There are a lot of different options here because Western training for combat was a highly personal experience dependent on the student’s master and, for the Middle Ages, tied heavily into ascension into adulthood rather than the regimented militarized structure or the comprehensive training systems we see coming out of, say, China.
So, the answer is when her father decides its appropriate for her to have one. Which is usually the point where he decides she can be responsible with it, and not kill herself or someone else. She still won’t be allowed to use it, but she can carry it. If she comes from a wealthy family then she’ll go through a few different swords because she’s constantly growing. If she doesn’t, she’ll probably just get the one she receives when her apprenticeship ends. Or whenever she has the means to buy her own sword from the local blacksmith, one that’s built to her specifications.
Carry and use are two different terms. Having and using are also separate terms. Your character can receive a weapon for the purposes of their training that they’re allowed to carry but not use.
You’ll need to study up on Western combat, specifically the era you choose to base the “historical” part of your historical fantasy on. With the resurgence of HEMA, there are plenty of fantastic resources online you can turn to for advice on sword combat. Matt Easton’s scholagladitoria channel is a great jumping off point. This can be great for defining the culture your character comes from and the type of combat she could expect to engage in. This, in turn, will hone the type of training she received from her father.
Writing a character’s training can be very difficult if you don’t understand the specific type of combat your character is going to engage in, and “sword combat” is not specific. There are lot of different types of swords with hundreds of variants in how to use them, and many that had their own specific purpose. Outside the Renaissance nobility, most sword combatants weren’t duelists. Duels, historically, were used as a means of settling legal disputes. While there were duels, the Middle Ages was more about various warlords fighting over territory. Their knights trained to engage as heavy infantry or heavy cavalry or both. They were usually trained on multiple different weapons, riding, hunting, and developed many other skills to aid them in warfare.
For purposes of writing your female character as a combatant, you need to forget she’s a girl. My answer about when the weapon gets carried would’ve been the same if you never mentioned the character’s gender. There are plenty of women who were, historically, trained in sword combat by their parents or were warriors due to circumstances. Too many for them all to be one offs or exceptions. The big thing to understand though is that the training doesn’t change regardless of whether your character is male or female. Her father would give her the same training he would’ve given a son.
If you haven’t considered filling your story up with female fighters in a universe that’s supposed to be gender neutral in terms of combat, then I encourage you to reconsider. To go any other way is to engage in a disingenuous girl power fantasy that does more to emphasize the female character’s special nature than it pushes the narrative that “women can do it too.” Normal requires there be more than one, and there be variety. This can be done specifically through minor characters peppered throughout your narrative, not just warriors or leaders but blacksmiths, farmers, merchants, etc. There also can be no, “but you’re a girl!”
She’s the rule, not the exception and therefore no one will give a shit.