Retouching a photograph, specially that of a famous model, is somewhat a touchy issue since there are no boundaries defined for it and when you think you are just doing your job right, people might still be offended with their image being manipulated in so many ways. In my opinion, the main purpose of retouching is to improve a photograph, which may include color correction, improving the clarity, clearing out any distractions or noise and since in this case we have a model's photo so we might just need to enhance the features or perfecting the skin, which may include changing the color tone of the skin or to shrink or enhance the physical aspects accordingly, just to make a photograph the best version of it.
As a re-toucher, one must have the responsibility to acknowledge that no matter how hard you have tried to make the image look better, there will be people who still might judge your efforts as demeaning. So its solely in your hand how you act and edit different pictures of different subjects differently.