Strong shoulders, strong arms.
In all honesty, the bow is a weapon you build to as a hunter. The first weapon she’d have learned was the sling. More useful for small game, and you can be deadly accurate with it. The David versus Goliath story in the Bible isn’t actually a joke or overblown. A child taking down a grown adult with a rock and a sling is entirely plausible if said adult isn’t wearing a helmet. The sling is the weapon of children everywhere, shepherds and hunters. In many parts of the world, they still use it. It’s also better for small game. Katniss would’ve done better braining the squirrels with a sling rather than a bow, like children do.
As a child, she’d be trained on a child’s training bow and work her way up the different types of bows practicing on a single target. The longbow is a weapon that requires a fairly hefty amount of upper body strength to wield, and she’d have to work and train up into her early teens before she was allowed to use it for hunting. The amount of strength you can draw dictates how far the arrow flies and how deep it penetrates. Depth of penetration is important, as is how far the arrow flies. Both define how close you need to be to your target in order to be successful. Herbivores don’t stand around waiting for a predator to kill them, and carnivores might just decide turnabout is fair play.
So, most of her childhood was spent on dummy duty with her bow as she learned to clean and care for it. Learning to stand, and that’s a whole series of lessons. Learning how to string the bow, learning how to hold it, learning to draw before she was ever allowed to shoot.
What whoever was training her would set her on before that is the other skills, and she’d act as a gopher for them the way all apprentices do. Following behind the older hunter, carrying their equipment, watching them and acting under their direction. You can’t hunt if you can’t find game, and you can’t eat it if you can’t clean it.
Hunting comes with a necessary subset of skills which allow the hunter to work. They don’t just go out into the woods and kill shit then come back. It requires patience. It involves waiting in one place for an animal to come by, sometimes for days. Traps, tracking, reading sign, learning to move through the underbrush without disturbing it, hiding your scent, etc.
Your hunter will catch more food that they eat on the regular with snare traps set for rabbits and other small game than they will with the bigger game like deer. Bigger game takes more investment, more energy, and a lot more luck. There’s also a higher chance of injury.
There are plenty of herbivores that won’t go down quiet, deer included. If your hunter hits wrong and they sense/smell them, there’s always the chance they won’t run and will come right in after the hunter. Animals have “fight or flight” too, and a doe can gore you just as well with her hooves as a buck can with his antlers. Any poor soul chased up a tree by a moose or just gut checked by a horse can tell you, herbivores are assholes. On an unlucky day, they’ll kill you just as well as a carnivore and that’s if you can find them at all.
The chances of managing a “one hit kill” with an animal like a deer are low and, even if you land a killing blow, they’re not just going to fall over dead. You’ve got to be able to follow it, recover the body, and kill it as it lies there bleeding out on the ground if necessary. You’ve also got to have some way to carry it back. Then, there’s the risk you run with whether the herd animals will return to the same place or move somewhere else if too many of their number die. If they do, and they’re your primary source of food, then you’ve got to move with them. Nevermind that there are quite a few animals a bow is simply no good for, like bears and boars. Where you need other tools like dogs and spears.
Hunting is a complicated business, and it doesn’t come with any guarantees.
Now, those skills do translate over well on a certain level to dealing with humans. Though, it’s not the weapon skills so much as the other less flashy ones. Many scouts in medieval armies, for example, were hunters of one sort or another. As were the foragers tasked with feeding them. The ability to tell how many people passed, where they passed, and what they brought with them from the tracks left on the roads or in the hills was a valuable ability. The ability to move through the woods without being seen, to hide your passing, to tell who is breaking trail, and to find their camps was also helpful.
The Ranger class in DnD is built on the hunter. You want a character who has more in common with Aragorn than Katniss. Aragorn uses a bow, but it’s not his only weapon.
The reason for this is that the bow isn’t a great weapon for close quarters. More importantly, it takes time to prepare. You don’t travel with it strung, as that wears out the string. If the string is no longer taut when strung then you can’t fire the bow. You don’t travel with the wood left to the elements. It needs to be wrapped, and packed away. Constantly be oiled to maintain its elasticity/limberness so it can be drawn. A dried bow is a bow you can’t pull, no matter how strong you are. You also can’t get it wet. It’s a weapon which takes a lot of prep in order to be used, a lot of care, a lot of maintenance, more than average, and a lot of hard work.
When you’re in, say, a military or part of a raiding force that knows its attacking then that’s great. Or someone who is on watch for certain periods during the day and will be relieved by another, that also works. Or when you’re sitting alone in the woods waiting for an animal to come by. However, the necessary prep time a bow requires is a lot less helpful when you’re taken by surprise.
By the time you’ve taken it out, unwrapped it, strung it, you’re dead. The enemy was also probably too close for the bow to really be of help anyway. Its a weapon which requires distance. Awesome when you’re pegging people from the ramparts, halfway up a tree, or fifty to a hundred feet off. Less so when they’re standing over you, axe in hand. The traditional role of archers in a military structure is artillery, and not that different from how we use the modern one. Their purpose is bombardment, they soften up the enemy so the vanguard can break their lines and kill them.
There is one kind of single combat the bow is useful for: stalking.
The bow is a silent weapon, and when used in a hunter-stalker mode, can be terrifyingly effective. It’s a stealth weapon, meant for ghosting in and ghosting out as you pick your enemies off. However, this kind of combat requires a proactive mindset and a willingness to get your hands dirty.
It’s also vindictive and, from the perspective of most modern morals, it’s cruel.
Humans are no more lucky than animals when it comes to hunting. The bow is the slow death. No character, no matter their skill level, is going to be guaranteed clean kills. However, what they do get is debilitating blows. An arrow through an arm, a leg, or better a lung, is going to take enemies out of the fight and if they’re not dead yet then potentially another one with them. Harassment is the order of the day. The slow path of carving off opponents, damaging them so they can’t fight back, following as they try to run, before moving in for the kill.
It’s a predatory style of combat, it is (really) just hunting. Hunting humans instead of animals. The terrifying form of combat that haunts so many horror movies. It’s psychological warfare.
However, it’s the kind of combat that takes time, patience, and a strong stomach. It’s up to you to decide if that’s the kind of combat you envisioned for this character to participate in. Or the kind of story you want to tell.
People embrace the Predator and Lara Croft from Tomb Raider (2013), and countless others that have this particular combat style.
It might, however, behoove you to consider coming up with other weapons this character has familiarity with. From knives, to traps, to fishing lines, to other more improvised weapons built on the fly. This character has a range of options within their skillset, and there’s no need to stick to just one.