It goes without saying that women typically have different body types than men and this fact often never gets addressed when guitarists are speaking on how to position a guitar when standing up. It seems that my breasts either make it near impossible to play in the "correct" position most teachers preach or that I hang it low enough they don't interfere yet lose some dexterity on the neck and power in strumming. Even when it is in this lower position, however, the neck is still pushed outwards and the guitar lies flat against me so I cannot see what I am strumming at all. I doubt this would be a problem with an electric seeing as how thin they are, but my acoustic is a very thick big sort of fella. Now, I do also primarily practice sitting down so I would guess that some of the difficulty is due to being unfamiliar with the standing position but I am having the darndest of times replicating it while seated. Any tips on where I should have the guitar fall on my person or how to create the same position when seated would be very helpful!
I'm going to post the dissenting answer here in that I feel like you don't want to look for a different kind of guitar or a perfect strap height. Most of my time in bands has been with at least one female guitarist or guitarist/bassist in the band, and in one band that I was in for a few years I was the only man. I also am a big fan of several bands feature women guitarists, including Sleater-Kinney and most importantly Indigo Girls, which is fronted by two women (Amy and Emily) who spend most of their time on stage playing full-size steel-string acoustic guitars.
Amy and Emily have each gone through different (human) body sizes over the years, although they have both been women the entire time. When they play acoustic guitars, they often play full-size dreadnought style guitars, which are the second largest common body style for acoustic steel string guitars (the largest being jumbo). Let's look at a picture (note, I believe these particular guitars are one size below dreadnought, but the picture is ideal in other ways):
Image Source (Amy on the left, Emily on the right)
I think this image is an excellent example of common guitar usage by women, which I want to note is pretty much identical to how men wear and play steel-string acoustic guitars.
So my answer to this question is: Use normal guitars - choose them based on sound and playability, not on being able to see the fretboard while standing. Learn to play, especially strumming, without looking at all. When you do have to take a glance or even a longer look at the fretboard, don't expect or try to have a good full on look. Tilt the guitar up slightly, lift it with your body and your fretting hand, and look across the fretboard to keep a sense of where your hand is. Train your muscle memory so you don't really need to look, instead you're looking just to have that extra assurance for a live show.
For comparison, here is Sleater-Kinney:
Image Source (Carrie on the left, Corin on the right)
Carrie (Brownstein, also of Portlandia fame) is one of the best active guitarists in the world right now (in my not-very-humble opinion). She pretty much never looks at her guitar, she jumps around and gyrates pretty much the entire show, and she never misses a note. I think we can assume she practices hard. So you can aspire to being like Carrie.
Corin (Tucker, also of the Corin Tucker Band) is not so much of a perfectionist or so athletic on stage. She sings like a banshee (in a good way) though, and therefore doesn't have a lot of time to look down. This is one example of her looking, and again, she's doing the same thing that men do. Almost her whole body is involved in the process of looking at her fingerboard. Her weight is on her toes because she's bent forward slightly at the waist. Her back is curved, shoulders forward, and most importantly, her head is down with her neck out. This is to get her face and eyes to be forward of the front of the guitar. Depending on the type of acoustic, it can be hard to crane one's neck far enough to see properly (which seems to be the question at hand).
This is about the least-badass pose possible for anyone playing guitar. Corin can get away with it because she is badass in pretty much every other way possible. Note that even folk rockers like Indigo Girls need to keep a bit of badass-ness in their stage presence, and they put on probably the best live shows of anybody ever (really, go see them if you never have, just go do it).
Again notice that even though Carrie's guitar is kind of high up, both women wear their guitars below their chests, which is again common for men as well.
Work to be like Carrie and Amy, and allow yourself to be like Emily and even Corin when you need to be. When you're learning something on an acoustic from scratch, start off seated so you can really look at what you're doing. After you've got it down, discipline yourself to practice and rehearse without looking. Then when you get to a live situation, the poor visibility that you'll get with your quick glances and/or neck craning will be enough to ensure an excellent performance, and you'll be able to strike all your badass poses the rest of the time.
You may need a different acoustic guitar. Go to a music store with a wide range of acoustic guitars and try guitars of different body sizes and scale lengths and see what is most comfortable to you.
Being of the male sex I cannot speak to your situation directly, but I would point out that acoustic steel-string guitars are available in a range of sizes, from the largest to the smallest: jumbo, dreadnought, grand concert, grand auditorium, concert, and parlor. In the traditional Martin parlance, they are jumbo, dreadnought, 000, 00 and 0 - sized.
I'm aware that many women choose the concert and parlor sizes, although there is certainly a difference in tone and projection with the smaller bodies -- that is by design.
In addition to the body size, different models of guitars differ in the depth or thickness of the body, which could certainly be a factor in your case.
It's also possible to select a guitar with a thicker or thinner neck, a different neck shape, a different fingerboard width and a different string spacing at the bridge.
It's also possible to select a guitar with a shorter scale length, which makes it easier to finger if you have small hands.
There is one design for an acoustic guitar that is more or less unique to one company, Ovation, which incorporates a bowl-shaped back made of a cast synthetic polymer rather than the traditional flat wooden back. Ovations are hard to find these days although they are being made in the USA once again. You should try one if you can find one.
The front of the Ovation acoustic guitar
As for the position that you hold it on the body, guitarists of both genders are notorious for slouching horribly when the play seated, but the conventional wisdom for males is that you use a strap while seated to hold the guitar in more or less the same position that it sits against your body when you are standing.
In your case you should investigate trying the position traditionally used for a person playing a classical guitar (as opposed to a person playing a steel-string acoustic guitar): assuming you are right-handed, with the body of the guitar resting on the left thigh and the left leg elevated; versus the acoustic guitar position, with the body of the guitar resting on the right thigh and both feet at the same height).
Traditional classical guitar posture with an elevated footrest
Traditional classical guitar posture with a guitar brace attached to the guitar, so you can keep both feet flat on the floor. This is a posture with less stress on the body.
The usual acoustic guitar slump (which you might find to be stressful on your neck and back after awhile. Stand up and stretch frequently.)
A number of years back, I found a solution which helped me position my guitar exactly where I wanted when I was standing up. The answer is a string running from the strap button, across the top of the lower bout of the guitar, to the strap at the other side near your shoulder. This lets you angle the guitar neck however you want, adjust the guitar balance across your body, and also has the side-effect of lifting the face of the guitar so you can see the fretboard better.
At the time, I put a little page together about how I did it. As far as I know, no-one else has ever used it. :) Never mind - it still works for me, and it might work for you too.
For a reference, you could look up for guitar players who may have a similar body type as yours, and try to figure out how they are getting comfortable at what they are doing.
Playing while standing up will always feel different than sitting down, so with time most players figure it out automatically. Just make sure your strap feels comfortable to you.
A few examples: If you compare the standing stances of Slash with that of Dimebag Darrell you will notice each have their own unique style.
I think that probably you just have a too big guitar. Some steel strings come with absolutely huge bodies that are in many ways very unpractical. Something like a Taylor GS Mini or even a Baby Taylor could work better for you.
I would especially not advice you to play a dreadnought body as they are very thick at the neck. A shape that has most of the girth at the rear and slims out at the neck is probably your best bet..
It is just something you have to figure out for yourself. As you mention people's bodies are different. There really is no one size fits all solution.
A long skinny person and a short overweight person will have to find different solutions to these problems.
You are not going to replicate it. Especially not the classical position. You have to practice this new posture until you get the hang of it.
For reference here is the Taylor website. You can see a visual representation of the body shapes there.
I have no gender-specific advice, but this is what I do to get a guitar into a good position while standing: While in a good sitting position, I adjust my strap until I can stand without the guitar moving significantly.
You may need to experiment with different kinds of straps. Tied to the headstock or using a second strap button will be different. Maybe a Mariachi style strap would work better for you. Maybe some sort of dual-shoulder strap. Maybe the option from Graham’s answer. And there are likely other options out there as well.
Credit to other answers: I do believe you could benefit from experimenting with a different size of guitar. Note that the size of the guitar effects the way it sounds. I like smaller guitars, but you might like the punch of a dreadnought and may not want to compromise. I believe that you could learn to handle any guitar that you love, even if it may not be the easiest guitar choice. Not knowing your particular build, I must admit that I have seen some players where the dreadnought or jumbo was not possible because of a combination of height (short), belly(large), and chest size (large) but it is not a universal problem for all women. It is also a problem for some men and younger students. A search for Dolly Parton plays guitar, shows her with mostly small guitars but she also has large ones and plays them seemingly without issue.
Seeing the strings and the fretboard: You may need, from time to time, to look at your hands, if your technique is correct it should not be from a very good point of view. Use your imagination, touch/feel, and practice to see through the guitar and make up for what you can't see with your eyes. You should never be able to see your left hand fingers connecting to the individual strings (electric or acoustic). If you can, your technique is wrong. You are twisting your wrist back or bending it too much, doing something really weird with your neck, or perhaps some combination along those lines (What Wheat calls the acoustic slump). It is possible to learn to play without seeing your hands. That's how I play most of the time. Some people are constantly looking at their hands and seeing their hands on the strings while they are playing, but I have never seen someone like that make it through a live performance.
Actionable ideas: (Aside from changing your guitar) I liked the comment about closing your eyes sometimes when you practice. Another thought is to practice in front of a mirror to see your hands. This is difficult to do this since everything is backwards, but once you get a little practice at it can give you a better understanding of your own technique and how to improve, plus it will keep you from looking at your hands in a way that is a bad habit or technique.