I was about to ask how young she was, thinking after getting out of her "baby fat" phase she would have glass-cut cheekbones, but she's 28 so that won't happen.
I think, cheekbones would be the first to show from a weight loss, look at her body/ stature, she isn't the most delicate woman, more broad and Diana looks 'heavy' without being heavy or being thick, so I think she belongs into the category where the face would be improved first then the rest of her body.