She is beautiful, but she has always been tiny if you look at older pictures of her. I don't think she has a special diet. At least not that I know of.
But for you. To loose hip wait I would work out with lunges or steps.
And for your waist, you COULD do crunches, but since you only want to loose an inch you can change your diet up a bit. Stick to high fiber, low fat food. Try to stay away from carbs and eat lots of salads and greens. Find a good way to make salads exciting for everyday like adding dried cranberries or cherries, or fresh apples and walnuts. Oh and stick to vinaigrettes and fat free dressing, nothing creamy.
Hope that helps =)