What is the big deal about being seen in the same outfit as someone else? It's ridiculous, if Mary buys off the rack designer clothes, which she does, and mixes with a particular echelon of people that can afford these clothes also, it stands to reason that it will show up on someone else...Most famous case in point, the purple evening gown with wraparound satiny sashes worn by Sarah Ferguson, then shows up on Mary who wears it more than once, you all must know the dress I am referring to?
I am not saying Sarah gave Mary the dress, no, no...but just to make my point that Mary has been seen in a dress photographed on someone else (famous) before her and it is obviously not an issue for Mary...so wearing a hand-me-down from a friend less photographed than her, would not present any problem as far as I'm concerned...
And all I am doing is speculating and having a bit of fun with it, surely it is not an important issue to take so seriously...Your defence of Mary is admirable, but I think she does alright on her own...