Awesome art; I love how you sweat the details. The flow of cloth for her skirt and loose blouse are particularly convincing. Great coloring too. I have to agree with your description; something about Carrie Fisher's face is very hard to make an accurate likeness. I always fail at that myself. Oh, and it's nice to see her, ah, proportions are accurate to Fisher's real measurements at the time. (Although like every other fanboy I always imagine her as voluptuous!)
OH my, this is epically awesome! I must say that I love the pose and the stern look that are very imposing (strong just like Leia is (after all she's the daughter of Darth Vader) should be), the background just complements the hell out of the piece all around! While you believe the likeness of Carry Fisher to be a failure, I must say that in this style you have given us a real Leia--what she would REALLY look like in its OWN world--I love that you have that spin on it. Love it! Great work.
I tend to fav and run, but I have to say, you really captured the essence of Leia here, even if you didn't make her look like Fisher, you have made her clearly the stubborn gun wielding princess. Kudos.