Amanda Platell: So you don't like the stepmum? You should meet her daughter

We would have preferred Yvonne Sherrington were she a plump little thing with a penchant for M&S

Move over Heather Mills-McCartney - your mantle as the most vilified stepmother in Britain has been snatched by another. Enter the leggy Yvonne Sherrington, former dancer and the woman who tried to strip her dead husband's children of their £10m inheritance with a will cooked up by her own daughter.

This is a woman so horrible, a wife who made her husband, Richard, so miserable, that his brother said death was but a blessed relief.

So nasty her own husband nicknamed her "Hitler". Coming from a devout Jewish family, that's quite some insult. He also called her The Witch. She was only interested in his money, he told friends, before dying in a car crash seven weeks after he signed the will leaving everything to her and writing his kids out of their share of his millions.

It was every child's nightmare. Their adored dad divorces loyal mum (so loyal she put up with his mistress, Countess de Rosenthal, for 12 years), and falls for the charms of an expensive divorcee with two children of her own. The whirlwind courtship ends in marriage, but before long distraught dad is sneaking home to ex-wife Gloria for chicken soup. Suddenly he dies and they discover the Witch's daughter has drawn up a will, signed by dad, leaving everything to her mum, proving that the only thing worse than an evil stepmum is an evil stepmum's daughter.

Judging by the designer wardrobe in which Mrs Sherrington turned up at court day after day, I'm surprised there's any money left. Not since Bonfire of the Vanities have I seen such an extensive and exquisite collection of power pinstripes. But pinstripes do not a Witch make.

Quite how Mrs Sherrington's daughter Nathalie felt her PhD in plant ecology qualified her for drawing up the will in the first place is beyond me, especially a will that meant if stepdad died first, as they usually do, everything would eventually end up going to her and her sister.

The fact that Yvonne Sherrington looks like a cross between Edwina Currie and Julia Roberts has not helped her case. We would have preferred her if she were a plump little thing with a penchant for Marks & Spencer, rather like the first Mrs Sherrington, not a rather attractive 55-year-old walking designer shop with a killer glint in her eye.

But hold on a second. OK, so she tried to stop her stepkids inheriting millions. But is our reaction to her fair or are we just engaging in that time-honoured obsession, stepmother bashing? And, while we're at it, why are there no stereotypical evil stepdads? Personally, I got my prejudices in early, hating stepmothers ever since one was so cruel to poor Cinderella. And aren't the daughters always the most evil?

It was no better in my favourite teenage book Jane Eyre. Jane's ghastly stepmother tormented her, then sent her off to that terrible school where she nearly died. No wonder we distrust them.

It wasn't until The Brady Bunch hit town that we saw even a glimpse of a nice stepmother. And she was the best; kind and fun, and loved his and her kids equally, as it should be but seldom is.

The second Mrs Sherrington aside, I fear the stepmother has become a modern-day repository for any kind of dysfunction in the second family, of which there are now so many. For the stepchildren she is a target for all the disappointment and pain of trying to fit into a new family. Of course kids hate it when dad shacks up with someone else. And it's easier to hate a stranger than your own father.

And part of the problem is that the stepmother's children usually stay with dad in the new matrimonial home while his own children only get to live with him every second weekend, if they're lucky. So the stepmum gets hit with all the jealousy they feel towards her kids and the relationship they have with their father.

Stepmums get a rough time. The simple truth is, most children would prefer their parents unhappily married to each other than happily remarried to someone else. Yvonne Sherrington is a gold-plated gold-digger so transparently greedy the judge had no compunction in ruling against her and for her stepchildren. She was a one-off. It would be a shame if she and her pinstripes were to give stepmums everywhere a bad name.