A good fun shot, but I've got to agree with the previous comments, especially those about the visibility of the wings, the composition, lighting, etc.
With respect to (wrt) the wings, I first looked at your image on an iPhone and, for quite a while, I actually thought she had a guitar case over her shoulder, wide end up. Look at your image at many different sizes, from very small (to give you an overall view of the composition) to very large (to give you a view of details and technical features such as sharpness, small areas of blown highlights, etc.)
WRT composition, it doesn't matter if it's a fantasy composite or a normal photo, the same compositional guidelines apply: (a) you've got to decide which are the one or two most important points of interest in your composition, and then steer the viewer's eyes to those points; (b) generally, you don't want to have a person near the edge of the frame pointed out of the frame; (c) you don't want ultra busy backgrounds that attract the viewers' eyes away from the main subjects; and (d) you want believable sizes and lighting for the various elements of your composite.
WRT lighting, obviously it should come from the same direction for all elements of the composite, but I wanted to point out that if a person is going to be a main compositional element, be careful of mottled lighting over her face. It isn't just a matter of the high contrast, the other problem is that the highlights often are warm toned, whereas the shadow areas pick up the green ambient glow in a forest. I had to make a special effort to smooth out the lighting on your wife's face.
Towards this end, I played around a bit with your image trying to keep the fantasy fairy-in-the-forest intent by softening the background and giving it an unusual color, and zooming in to make the focus be clearly on her. The version you posted reminded me of photos that my dad used to take where he would be so far away that the family would be tiny little specs in the picture.
See what you think.
Tom M