very noisy, and out of focus. The poses are.... different, lol to say the least. I give you that.
#1 and #2 are underexposed, noisy and seems to have blown highlights.
#4, my eyes are drawn straight to that huge white structure.. and takes away from your friend.
first thing I have to say is WHOA you live close to me haha and now for the CC
some look noisy and others are over exposed in spots. I would have to say my favorite is the 4th one imo its the best what would make it even better is if it didn't have that overexposed building in the background
The crop on the edited version removes the really white eye-catching building thing, but now one is more apt to key in on the very odd hanging fold on the front of her sweater.
Here are some other technical points - the graininess on all of the images is due to the high ISO. Your exif reveals that the ISO was 1600 on all images above. Unless you use an on-camera "High ISO Noise Filter" like many Nikon DSLR's have, you're stuck with the noise. (That's not a cure-all by any means, as it in itself creates other resolution problems, but it would at least have toned-down some of that grain.)
As well, two of the frames are using 3.2 second exposures. As with the above note on High ISO noise reduction, using an on-cam "Long Exposure Noise Reduction" would also have helped with the graininess, along with a tripod for more clarity. However, this being said, while the tripod would keep the inanimate things clear, your subject is human and, being that we breath and twitch and move, will not be motionless (nor clear) for that amount of time!
Some other observations. EXIF shows the shortest exposure at 1/5. Still too long. As someone said above, bring light! Finally, all of the shots are at f 8, which is a part of the reason the background isn't all that blurry (probably should be), as well as why the shutter speeds are so long and ISO is so high. Shooting all of these at around an f 2 would have helped a bit.
Some positive thoughts! Take a look at her expression. She is very comfortable and genuine. Even though you've got some technique and posing things to learn, you obviously have something that a lot of wanna-be photographers would give anything for. What is it? An honest and active interest in other people, and an ability to interact casually and comfortably with others. Yes, she is your friend, but don't forget that a photo shoot can be a highly artificial experience. Your interaction with her was not. This is a very good thing!
definately good shoot to learn from in the future. I would have her wear a sports bra or something if she does another head stand... it looks like shes about to fall out... and to me it doesn't look that faltering she is beautiful and I look forward to seeing some more pictures