It’s certainly within the realm of possibility. There are plenty of ways to do it, but it’s unlikely to happen with just their bare hands. More likely to happen with a weapon, probably an improvised one in this situation like a liquor bottle, a pan, a piece of metal pipe. And then, she just gets lucky. Maybe she clocks him across the head. Once, twice, three times, maybe she loses count.
She’s scared, maybe she’s angry. It really depends on the scene and how you want the other character to die. She does, probably, need to come at him with something but she also probably didn’t mean for him to die. Maybe she wanted him to in the moment, but didn’t expect it to happen and didn’t really want to anyway.
Shock comes next. Disbelief.
“I killed him. But… I don’t understand. I did? How could I? How could I kill him? He can’t be dead!”
If you want to play up the whole, ‘But I’m just a girl’ angle then this would be a good time. It’s pretty important to play up the sense of desperation, the fear, the terror about the consequences.
She could also push him down a flight of stairs, or he falls in a struggle. Hits his head. Doesn’t get up. There are a lot of ways for someone to die accidentally. Head bashed into corner of table is a good one, actually. Where it connects with the temple.
It’ll be a scary scrabble, though.
If you’re asking can she suddenly become a martial arts master and kill him with her bare hands in the midst of an “instinctual response” due to adrenaline? Then, no. That’s not real.
Killing someone accidentally in an altercation? That happens and more often than you might think.
Suddenly developing high level martial arts skills in the manner of suddenly going, ‘I know kung fu’ like so many novels? No, not so much.
Your body does not instinctually know how to fight or defend itself because combat training is actually about subverting those instincts. Introductory level hand to hand combat is about exploiting your natural instincts through extensive training. You’re not going to just develop those skills because ‘crisis’.
If you’ve never experienced a flood of adrenaline before, then understand that adrenaline in this situation is going to be counterproductive for her. It will transform you into a shaking, jittery mess. It’s going to be just one more thing for her to overcome, unfortunately.
Rage is the same way. Anger will become more helpful when she’s losing track of how many times she’s pounded a metal re-bar into his face. It’s not so helpful leading up to that because of the way it blinds.
Controlled anger can act as motivation and the same is true with adrenaline, but she has no training. Her body’s natural instincts are far, far more likely to become debilitating and/or result in her death.
She’ll have to fight through that.
What your character has is her brains, her guts, her ability to keep her fear from paralyzing her, maybe the ability to utilize it, and her own ingenuity. She’ll probably be terrified, shaking from the adrenaline, maybe crying, her heart pounding so hard in her chest that she feels like she’s about to faint, and acts to save her life. Then, her actions have unintended consequences as in his death.
If she’s bought into cultural bullshit, then she may not know it’s possible for a woman to kill a man. Or even overcome a man. She may believe on some level, like so many ‘good’ people, that it’s not possible because you must intend to kill someone. The disbelief, terror, shock, and horror may all combine into her not understanding what the hell just happened even though the simple answer is, “What do you mean how? You beat him over the head until he died.”
This doesn’t mean that she’s stupid because, honestly, this is pretty common.
To recap: does she mystically know how to kill someone? No. Can she kill someone accidentally without understanding what just happened and without it being premeditated? Yes. It’s called manslaughter. It’s difficult. It may require an improvised weapon of some kind and that weapon will have to be pulled from whatever environment she finds herself in. It can happen though, it’s not even all that unusual. Media spends so much time painting women as victims, often automatically, that it’s easy to forget that they can and do fight back. They can and do kill, whether its accidental or premeditated. And you can do a lot of crazy, damaging, stupid, and often irresponsible shit when you’re scared. I knew a girl once who hit a kid, a ten year old, on her way to school and just kept driving. Not because she was a terrible or evil person, but because she freaked out, didn’t know what to do, and just kept pretending the problem didn’t exist. We found out about it because the cops came to arrest her at school for a hit and run. She was a normal teen, and one accident was all it took to go from that to being a murderer and a child-killer.
It isn’t nearly as cut and dry as some people would have you believe.
Honestly, if you build into the part where she’s terrified but acting anyway while trying to think her way out the situation a la a great many thrillers/horror movies and not suddenly transformed into a badass via “natural instinct” then she will be that much more compelling as a character.
You do more to establish her courage, her ingenuity, her willingness to overcome obstacles and fight for her survival that way. This will ultimately humanize her more for the reader and give them a point of connection.
It feels more earned, provides a solid foundation on which to build her as a character. It’s also much, much more badass.
I’d spend some time looking at horror or thriller for this sequence, actually. The scenes where female characters are creeping around their house, trying to avoid their attacker, trying to find a way to get back the upper hand or manages to take it.
Remember, real courage comes not from being fearless but in overcoming your fear. In acting when there are no guarantees of success. To get into the fight when there is no safety net and the odds are stacked against you. It’s not defined by victory, but by standing up when every other instinct says stay down.
We treat this as weakness for women a lot of the time. That a female character, more so than a male character, is somehow weak if they admit that they don’t know what they’re doing. They have to somehow be exceptional or magically prepared by their own bodies and rescued by it rather than them being the driving force behind their own actions. There’s a nasty trend with female characters which denies them the consequences of their own actions, whether its the narrative choosing not to blame them or them being excused or it being pawned off on something else like their body suddenly acting on its own or them blacking out.
Try to avoid that easy way out.
We all start out as small and scared. Sometimes scary stuff happens and we don’t quite know how it ended up working that way. It’s confusing, and it feels like it couldn’t possibly have happened to us.
Remember, while her killing him is probably an act of desperation, it’s not an excuse. Whether he deserved it or not, she still kills him.
Gnaw on how she deals with that.