By making them characters.
With female characters, many writers feel there’s an underlying need for them to be “better than” when it comes to combat. They can’t just be. They end up written in comparison to male characters, and whether it’s a conscious or subconscious belief that they need to be the “best, best, best” and better than all the boys or they’re worthless.
Sexism is pervasive.
Whether you’re male or female, the vast majority of media consumed over the years will have taught you that objectification is the status quo. And yes, both those two characters you listed are treated in their narratives as objects. Struggling to hit the societal standards for what a woman “should be” in fantasy, beautiful, desirable, wanted, powerful, but also dependent. The fantasy society dangles in front of us. The issue with the fantasy is that the fantasy woman in question is always an object. A vessel to insert your desires into and not an individual, not a person with their own wants and needs. Being the desirable vessel is what women are told they should want to be. It’s a woman’s duty to exist for the pleasure of men.
Why are the badass and the Mary Sue always stunningly beautiful?
For women, our physical attributes are paramount, linked intrinsically to morality and goodness. You can’t be a good woman if you’re ugly. If you’re ugly, you’re most likely morally moribund. Our desirability is a necessity, it’s treated as the ultimate form of freedom but is, in fact, the cage. If you can transform a woman from a person and into a fantasy, she goes from challenging uncomfortable gender norms to being “safe”. The vast majority of female characters that we’re told are challenging gender norms are actually safely inside the narrow band. What is treated as “girl power” is often just a different version of the fantasy, as much for men as it is for the women it’s ostensibly appealing too.
A woman’s narrative importance is determined by her fuckability. Many of these characters are at once both the hero and the hero’s girlfriend. They are still the hero’s girlfriend, while masquerading as the hero, and thus must be worthy of their love interest. They aren’t actually any different, we’re just told that the hero’s girlfriend is the protagonist now. And the hero’s girlfriend is a moniker tied to the man, her existence about the man, and not herself.
She must be accessible, objectified, and always within reach. Better but lesser. Capable of nurturing the hero, taking care of others, and self-sacrificial. Her backstory is about the men in her life, and often she’s had to take on a masculine role due to circumstances outside her control. She doesn’t “choose to be”, she’s “talented enough to become”. She’d give it all up if she could. She’s dangerous but not too dangerous. Outstanding enough to defy the gender constraints, able to run with the boys and beat them, but still deeply insecure in herself and looking for someone to “tame” her or “take care of” her.
It is a woman’s role to be subservient.
When you are a fantasy, you are no longer dangerous or in defiance of the status quo. You are not a deciding actor, but an object moved around by the narrative’s will. There to be pretty, no matter how much ass you kick in the meanwhile, until you go away.
There is no way to stop writing these characters if you’re unwilling to unpack the gender norms and societal expectations which creates them in the first place. You also need to stop writing them in comparison to men, with men as the norm, and the gold standard that they must defeat in order to be worthy of a role in the story.
Why does the badass need to be beautiful? Why can’t she just be brutal? Why does it matter what she looks like when she fights?
These characters can be mediocre and struggling, and it’s better if they are. Badassery is not a state of being. It’s a title earned through the character’s actions in the narrative. It’s not a single standard, but a contextually changing one based on the challenge.
A woman who fights to escape an abusive environment without violence is a badass. The teenager who studies all night in order to pass an exam in their worst subject, overcoming deep seated insecurity and self-doubt is also a badass.
Greatness is not what we are, it’s what we fight to become.
Women are asked to sacrifice their own desires for the good of others. So, let these characters ask, “what about me?” Fill them up with wants, desires, and dreams. Let them travel the path from mediocre to excellent. Weak to strong. Figure out their feelings and their emotions and figure out what they want. What they could be or can be, dreams that are perhaps stolen from them in context of their narrative.
Writing well-rounded female characters requires breaking past the fantasy in which we perfectly fit into society by the standards demanded of us. That we can fit into the dimensions, force ourselves into shape, while simultaneously defeating them. To recognize, whether male or female, that not only are those standards unfair, they’re also unnecessary.
If you’re stuck between the Mary Sue and the stone-cold beautiful badass, it’s because, on some level, you still believe a woman needs to be more than human in order to succeed.