Here's a dump of why Donna is so important to me as a female character and why I want characters like her in EVERY show.
First of all, she's not feminine. Or intentionally masculine. She's literally just a woman who doesn't give a shit, but also doesn't have to give a shit. She wears no makeup, her style is plain and utilitarian, there's literally nothing extra in what she wears — which obviously is somehow dictated by her role and the fact that she lives in a fucking haunted horror town, but anyway. Her hair is shoulder length, which is literally the most unintentional genderless style to me, because shorter hair would probably suggest butch more stereotypically, longer hair would be stereotypically more feminine and, more importantly, impractical.
She's not beautiful either. You wouldn't call her ugly or anything, but 'pretty' is just not her category. I also really like the fact that she's not skinny, and she wouldn't be this cool if she were skinny, because there's this unapologetic, physical presence about her that implies strength.
And yet, which is really important, she's not unshakable. She doesn't just do everything on her own, she isn't 100% confident. Moreover, she's breakable, and it's been shown many times. She has feelings and worries, but it's the fact that she struggles that makes the viewer see her as strong. There's also nothing special or 'heroic' in an action way about what she does, she's just doing what has to be done, and this is so much more, because it's real and even relatable.
Second (or third, or wait, where was I?), to the great joy of my asexual ass, there's no romance implied, involving her. As much as I love the headcanon that Donna is a lesbian, I'm happy that she doesn't have an explicit partner in the show and all of her relationships are based on respect rather than attraction, and it's just so good.
Finally (or maybe not, because I could actually talk about her forever), her interactions with Boyd really are the heart of this show for me, because 'two people who dislike each other but have to work together to survive and thus turn into something close to friends but not quite' literally is my favorite trope.
