So I currently have only one character. Charlie.
She's pure human. No special mumbo jumbo or anything like that. Supers kind of freak her out and she really just wants all of you crazy people to leave her alone and let her get on with her life, as uneventful and exciting as it is.
(Which is why you all need to drag her into your crazy super plot stuffses!)
She's absolutely adorable and sweet, and genuinely nice. Has a bunch of quirks (mild OCD and anxiety), but is very friendly and outgoing. She's a delivery girl for Cat's Couriers located in downtown Seattle. Cat, her boss, is a total sleazeball and tries to bang all the ladies with varrying degress of success, and since Charlie won't touch him with a ten foot poll he gives her kind of a hard time.
I will happily be your delivery girl. Discreet, Twenty Four Seven, Same day delivery services.
I don't have any specific plot for Charlie but I sort of see her just constantly getting caught up in the supernatural stuff. Not as any sort of indespensible person, but as that person that always just happens to be at the wrong place at the wrong time and gets dragged along and caught up in it.
Eventually I see her getting too deep to get out, as in she inadvertantly learns/sees/whatever something that she's not supposed to and the supers need to figure out how to deal with it.
I also sort of see one or more supernatural entities taking more than a passing interest in her. She's a human that has a unique job that could probably come in handy. Also. Adorable.
I am not opposed to her getting turned into a vampire or lycanthrope or anything, but I want it to happen naturally and not as part of a planned "let's go in this direction" sort of thing.
But that's all sort of vague and VERY long term and might change eventually. In the mean time: You need a random human girl for your plot? Count me in! You can fall into any of the above categories, or use Charlie as you will. Deliveries, a pretty face, random human, whatever.