He chin jutted up and forward is actually a much better pose than with her chin dropped. ANd, I do not mind the low camera vantage point one bit; it does make her "authoritative", and powerful, which I think is a good way to portray a woman of her age and physical attributes. I think the original pose and camera position would have worked better if she had stepped out a ways from the roses. You'll get better at photographing people with more practice.
I think you used the natural sunlight very well. The original shot has a good, strong under-chin shadow, which reveals the shape of her face well, and shows her strong chin and symmetrical face. The scene and the background (the telephone wire, the balloons, the rose bush) are not that good though. The other thing too is the "one-arm" pose...I'm not normally a fan of real-world poses where ONLY one arm is shown, and there's not a hint of the other arm. In a real-world, like back yard or front yard situation, and not some studio-concept shot, showing ONLY one arm often seems a bit, well...uncomfortable at times, and this is one of the times where that one shoulder and arm, with the obscured hand on hip, is kind of not helping the shot.
