This is a fine portrait, but it is a bit soft due to camera shake. You used 1/10th of a second shutter speed here, which would be equivalent to an image made at 1/40th or 1/60th of a second WITHOUT image stabilization. You used a very long focal length here, which is equivalent to 310mm, a focal length that would require at least a 1/300th of a second to avoid blur due to camera shake. The bottom line is that even with image stabilization, you can't make a shot with that long a lens at that slow a shutter speed unless the camera is on a tripod. Either a tripod or else live with the softness.
