Female geeks
If she's a security expert and software writer, you can't go wrong by reading about famous hacker/security expert Kevin Mitnick and seeing what sorts of traits, habits, etc. he has. Geekitude is not very gender specific, by which I mean that female geeks are not that different from male geeks in terms of their habits, clothing, etc. I know a ton of geeks--software engineers, roboticists, etc.--and I've never seen a female geek with a hairstyle that required any work at all; the "long ponytail" look is common. The one female geek I know with great-looking hair just naturally has thick black hair that grows in fat curls; all she has to do is let it grow. Female geeks with very short hair (e.g. pixie cut) are rare, perhaps because maintaining very short hair requires frequent haircuts. They usually just let it grow and cut off a few inches whenever it starts annoying them/getting in their way.
The key to both their clothing and their hair is that it requires as little work as possible. They are interested in other things, and if clothes/hair takes more than 0.01% of their time, it's too much. That's why "fashionable geek" is an oxymoron. They all seem to either pay no attention to their clothing (hence the "jeans + t-shirt + long-sleeve button-down shirt worn unbuttoned" look, which is as common among women as among men) or to dress in a slightly quirky way (unusual colors, eclectic, like they fell into the laundry basket and came out with random garments sticking to them). Geeks of both genders usually look slightly rumpled; when they look polished, it's because they have a presentation to give for NASA or some other funder. When female geeks dress in a polished way, they rarely seem to wear heels--usually it's black flats, or some kind of space-age looking shoe with a heel as wide as the shoe. In my experience, they also don't wear makeup unless there's a reason (e.g., some outside funder to impress), and then they don't wear much makeup.
Again, the key is not wasting time on things they're not interested in. This rule applies to food, too: if they can have a microwave next to their computer and put something in the microwave without taking their eyes off the computer, they're happy--that's what they're like in "work mode," anyway, i.e. when they're really focused on what they're doing, either out of interest or because they have a deadline. However, if they have time, like any other human being they enjoy leaving their workplace for a stroll over to the nearest cafe, just to air out their brain (the stroll, and not the coffee, is the point: being outside, possibly running into fellow geeks they know, etc.). They also go to restaurants near their work a lot, because it's very common for them to work late and they wouldn't waste time actually preparing their own food. A restaurant dinner usually provides leftovers they can microwave for lunch the next day. Obviously, there are exceptions--I know a male geek whose major hobby is gourmet food; he makes things like farfalle pasta with truffles and real, hand-grated parmesan for his one-year-old child--that's his definition of "mac and cheese"--so you can imagine what he makes for himself. But geeks who don't yet have families are usually as I just described above.
In addition to the sci-fi interests some other posters have mentioned, there is a sizeable contingent of techno fans among geeks. I know a geek who drove five hours to go to a rave where a favorite DJ of his was "spinning" (the verb for what DJs do), and then, post-rave, turned around and drove right back home to continue working on a project whose deadline was two days away. Working around the clock is common. This goes along with what I said earlier about food, clothes, etc.: geeks often neglect their bodies. The basic requirements of the human body, e.g. food, sleep, clothing, are often overlooked by geeks of both sexes; the body is a minor annoyance, something uninteresting that requires care, and they give it only the bare minimum of care in order to devote as much time as possible to the geeky things that interest them.
One odd detail: when I worked at a university that's famous for its computer science program, I saw a lot of female geeks who looked like they had PCOS (polycystic ovary syndrome). PCOS doesn't always manifest visually but when it does, the woman is overweight with bad skin, greasy hair, and some facial hair (I don't mean beards, but prominent hairs on the chin or cheeks or a sort of "furry" look between the chin and neck). PCOS is a hormonal imbalance whose main effect is to cause fertility problems, but in some women it creates this distinct physical appearance. I don't mean that a lot of the female geeks looked like this, just that the proportion of women who looked like this was markedly higher among the geeks of this college campus than it is in the general public. I have no idea why, although the physical appearance problems of PCOS are no doubt aggravated in geeks by their generally bad diet and neglect of their bodies. Also, it may be that women who look like this might gravitate towards geeky studies and geeky careers because popularity/success among geeks is not dependent on being good looking; geekdom provides such women a safe harbor they can't find in everyday society.
) I almost posted this in Tech Help, but it's a story issue, so I figured this is a more appropriate forum.
