Yet, the US first lady continues to fascinate us as the ultimate icon for the modern woman.
Wednesday was a case in point when she sashayed between serving up chow at a barbecue for military families,hugging schoolgirls and mingling with royalty - all the while looking utterly at ease and delighted to be in each setting.
Michelle radiated her characteristic warmth as she welcomed the Queen to a gala thanking her for Tuesday's glittering banquet at Buckingham Palace.
In an off the shoulder Ralph Lauren column dress that made the most of her statuesque, gym-honed figure, she looked stunning too.
Her royal guest, meanwhile, cut a typically regal figure, in an evening gown that shimmered with gold and silver sequins.
An unusual knotted diamond necklace, featuring emerald drop pendants and matching earrings, topped off the dazzling effect.
Inside, lavish entertainment awaited than 50 guests, including actors Tom Hanks and Colin Firth, David Beckham and author JK Rowling.