I agree with John on the diffuser. But I also notice the great park like setting you used to shoot these in. If these images are about the model, I probably should not have noticed all the pretty natural surroundings. The exif data is stripped out of these images so I'm not sure what aperture you were shooting at, but I would guess f8 or higher. Next time you might open your lens up a little say f4 or lower and try to soften the background up a little. Using a longer lens will also help in throwing the background out of focus.
"Nobody belongs to us,
except in memory"