This is a gorgeous take on Tawna. I especially love her outfit. Judging from the description, it's not even canon, so your creativity in that aspect is REALLY impressive!! I also like the little tufts on her knees and elbows; their simple design makes them a nice addition. The face is beautiful, too - sensual, but in a strangely "professional" sort of way. This will sound oddly specific, but she reminds me of a character who would provide a tutorial from a headset the player character is wearing...
I normally hate exaggerated hourglass figures in art, and while this is right on the border, her other proportions make it work perfectly. Your style of blending smooth curves into sharper corners (e.g. her elbows and other joints) also helps this effect along.
The only note I can give is that her hair is so tall it makes the placement of her ears kind of awkward. The shape of the rest of her head makes me imagine some bizarre antennae connecting her ears to her skull. Overall, I don't know for sure how I feel about the hair style. However, I can definitely appreciate that it's so different from most other renderings I've seen of Tawna, so I suppose novelty trumps anatomy here! :P
I looked at some of your other art, and while they're very nice, this is by far my favorite. I hope you keep going with your artwork. To that end, you are officially the first person I've scouted! I've also followed you to see how much even-betterer your art can get! (Wouldn't kill me to follow a SFW artist for once, anyway.)