Originally posted by Voytech In my defense, the background is not my liking, but was a forced thing.
That makes it a snapshot so from a critique point of view it isn't a defense.
You got pretty good perspective, would have been better if you had framed it without the little bit of neck, just below the shoulders would have been good probably.
Your aperture was too wide and shutter was too slow. At ISO800, that means you didn't have enough light.
For a great composition, try a background that is all one colour (black for example). Frame the chest and belly so that it occupies half of the frame. That will add shape to the negative space. An alternative to that would be a light background and backlighting then your wife's body will be in silhouette and if you get the lighting right, her body might glow at the edge.