Hi Aaron! I think it's a fun image that could be really appealing as a cover after some refinements. I usually offer tips on how to improve a current image without redoing everything, but you may consider what others have said. I would definitely consider what they've said as far as drawing issues are concerned. I hope you don't mind, but I did a rough paint-over, mainly concerning the color, though I did adjust her eyebrows and ear. Here are my thoughts:
I think the spot light was a bit harsh, so I lowered the brightness of the background. I used your midtone as the brightest spot instead. The shadows of her skin are very red. To unify the shadows with the background more, I color picked the mid tones in her skin color and moved it a little towards green on the color wheel and then darkened it, keeping it fairly saturated. I also changed her hair. Instead of blue, I moved it more toward green. Darkened the brown border on the left and added occlusion to the stitching. Adjusted the lighting on her face so it had softer transitions.0_1507526913505_aaron.jpg
Congrats on your first cover! It's a great start. Good luck.