So what happened when these girls put their wardrobes up for auction, as Di did last month and Janet last week announced she would (at Christie's Street Style Sale in September)?
All the papers went as orgasmic as they could while still being reverent about Princess Di - The Mirror even bought a dress as a prize for a reader. And last week the same newspapers went as poisonous as sad middle-aged men and uptight women can be about Janet's gear. "Decked out like someone from the Addams family," said the Telegraph of her; "wild hairdo, garish shades, blue lipstick and a see-through, knee-length black frock held together by Liz Hurley-style safety pins," wrote the Daily Mail of her at the 1995 British Fashion Awards.
The truth is that rather than being a winsome-dream-princess-turned-clothes- horse-turned-tragic-heroine, Janet has, through thick and thin, remained her own challenging self, moving imperially from husband to husband, from toyboy to old geezer.
Of course, she's pushy and outspoken, and growing old disgracefully, and I suppose she doesn't mind getting up people's noses. She must be long anaesthetised to being slagged off by the press.
But as far as clothes, and indeed looks, are concerned, I'm on her side. One glance round a newspaper editorial floor is enough to tell you that most people there should not be trusted with a line, even a thought, about clothes. Middle-aged editors thinking about their wives; dowdy executives playing safe - if you're looking for bedrock conservatism, news coverage of clothes for women over about 17 is where to find it.
In her twenties Street-Porter made her own clothes and was a creative trendsetter. For the party scene of Antonioni's BlowUp, that ultimate evocation of groovy Sixties London, she turned up with a silver PVC trench- coat she'd designed herself, and hair sprayed silver. She's still at it.
Pace the Mail, Mirror and Telegraph, I'd buy a used dress from Janet Street-Porter, but maybe not the one described as having perished armpitsn