The two chosen pictures are from the 80s, she's maybe 17-20 years and has extra weight. I can barely recognize myself when I look at my pictures from the 80s with that crappy hair we all had (Mary as well I see)
You could also have chosen these photos of Mary in her mid/late twenties where she has lost the babyfat, weighs the same as today and the fashion is more contemporary and she looks like she looks today.
Mary also seems to be one of those princesses who stay away from botox and cosmetic surgery. Thankfully.
Mary actually talking about it to the author Anne Wolden-Ræthinge in the book "Crown Princess Mary".
"As a woman you are exposed to so many pictures and influences. If you see a celebrity, a movie star or great singer in the media you don't know if you see a cosmetic embellished person. We have a whole population with perfect breasts! It always implies a little bit of loss of personality and lack of acceptance of who you are."