There is just one proper Fergie outfit featured in The Crown series four; a deep red velvet, puff shoulder dress, worn with large pearls, and glimpsed in the background of a family Christmas scene. It was a timid, weak attempt, really, compared to what we know of the real McCoy.
Who knows, the garish Yorks may get a bigger storyline in series five, when The Crown reaches the 1990s and both Charles and Diana and Andrew and Sarah filed for divorce.
But by then, fashion-wise, it will be too late. Fergie’s 1980s attire was absolutely her boldest, best costume era, and would have provided the most dynamic visuals when translated on screen.