If she wants to look like that, that's entirely fine. So long as its not detrimental to her health, I don't see what the issue is?
You may not agree with me and think i'm reaching but here are some reasons.
1) It's not only solely about her, all the IG comments are telling her to do her and she's beautiful. They are all lying. These comments are bad for her health and society.
2) Kids will see her, some will recognized the insanity, others who may be bullied in school or something will see her then read the lying outpour of comments telling her she beautiful and she may believe them and want to be like that too.
3) Children
4) "Morally positive" lying is spreading like wildfire on the internet, eventually people will actually conform.