Not sure if this is the effect you were looking for, I have found if using fill light move the the highlight side of the curve towards the dark to not blow the back light so much....I believe this does deserve an 8, for the composition and sharpness..
WOW! Now that's a beautiful photograph. Beautiful model and the fill light is perfect. I love the detail in the model's face and surrounding glow in her dress and the grass. I also think your choice of the slight angled horizon line works well here. Not much else to say but great work! Can't really find anything I would change about this shot. Bravo!