Does Cherie Blair matter? That was one of the pressing questions of last week, although arguably not the most important. There is a lot of her about at the moment, but is she someone we can afford to ignore? The serious-minded answer would presumably be yes. The serious-minded person would of course be missing the guilty pleasures of vulgar gossip, schadenfreude and righteous indignation that Ms Booth Blair has provided so richly for the rest of us and so inadvertently with her appalling memoirs and shameless interviews - her style combines Wag with Pooter - but what is there otherwise that is worthy of attention?

The awkward fact is that Cherie thinks she is going to be a judge and, given her high opinion of her gifts, a top judge at that. She already does some occasional judging as a recorder, although with typical immodesty she refers to herself as a judge already. What she does and says in public, and what private matters she chooses to reveal in public, do matter. It raises the question of what we might expect from a judge and whether she should become one.

Her chances of becoming a proper judge ought to have been finished at the time of her Bristol flats scandal, when her behaviour was tricksy and her public excuses accompanied by tears and ridiculous claims about having too many multi-tasking and mumsy balls in the air to attend to awkward details. Try telling that to the judges at the Court of Appeal: they will not be moved by sobs and lilac eyeshadow.

However, I hadn’t heard any murmurings that she was unfit for judicial office until last week, after extracts from her memoirs had appeared. A former senior judge, Gerald Butler QC, said that Cherie should resign as a recorder and had no chance of becoming a senior judge: “If she wants to tread this path of making money by outrageous comments, that is up to her, but I don’t think this is a job for a judge. It shows a complete lack of any kind of decency. It is the kind of conduct which demeans the legal profession. It is altogether disgraceful.”

More soberly, another lawyer, a senior barrister who sits on the Bar Council, said that “one of the important factors in being a judge is being able to exercise judgment, and part of that judgment is being trusted with confidential material”.

Throughout her time in Downing Street, and especially now in her book, Cherie has shown that her judgment is often abysmal and that she cannot be trusted with confidential material. If you read all the vulgar details about her tubes and ops and spats and hots, the whole gabby, greedy, sorry tale, you realise that she is not merely indiscreet; she simply does not do discretion.

At one point she writes: “I had never been taught the meaning of the phrase ‘discretion is the better part of valour’.” I could not help smiling. That is quite impossible to believe. It may of course be that in her impoverished dysfunctional home, with her saintly nan and mum, discretion was not much discussed, but at her outstandingly good Catholic girls’ grammar she must most certainly have been indoctrinated ceaselessly about the importance of discretion and those many virtues which come under its umbrella – modesty, humility, tact, delicacy, judiciousness, forbearance and truth. However, as with contraception, there are some Catholic teachings that Cherie has decided to ignore or couldn’t abide by. Perhaps temperamentally she is incapable of discretion.

That might not matter. There are plenty of pleasant occupations for people who don’t do discretion, such as journalism or making well-paid speeches. However, if there is one place where discretion is essential, it is the bench. Judges, so far at least, have been admirably discreet, whatever their personal foibles. The fact that Cherie envisaged no danger to her ambitions as a judge in writing and behaving as she has shows in itself that she is not fit to be one.

Some people have expressed surprise that she should have aroused such anger and contempt, particularly among women. The usual explanation for such unsisterly attacks is envy. And certainly there are many things a woman might envy about Cherie’s life. However, I think there is an entirely different and good reason for the resentment. Just as she is a disgrace to the law, she is a disgrace to our sex.

I hate to use the phrase “role model”, but I imagine that Cherie sees herself as one. Her book gives that impression. It’s true that she has achieved a great deal: to become a QC from a difficult background, even with an exceptionally good education, and even at a time of positive discrimination in women’s favour in the law, is something rightly to be proud of.

Her love of her husband and her extended family is endearing. People who know her say she is kind and funny, but publicly (and in this book) she embodies most of the things that people – men – told me in my childhood were wrong with women and why women could never hope to compete equally with men. I tried, and many of my women friends and acquaintances tried, to prove such people wrong. Cherie has done a lot to prove them right. She is the kind of woman who gives other women a bad name.

Women are so emotional, so impulsive, so irrational, I used to be told. Women are not logical; they are inconsistent and easily taken in. Women are so obsessed with status, with their husbands’ status and with material possessions. Women are indiscreet and gossipy in a way men are not. All this is true of Cherie Blair.

There was Carole Caplin. There was the outburst at the party conference about Gordon Brown lying. There was her use of the name Cherie Booth QC on Downing Street notepaper, a perfect example of a woman trying unfairly to have it both ways. There is her shocking gabbiness, her tabloid revelations about toilets and childbirth and fancying her husband rotten.

On top of that she is quite obviously obsessed with making money and buying properties, exploiting her husband’s office in the process with a sense of entitlement that is astonishing. In all this, rather like Diana, Princess of Wales, she is something of a heroine of our times, an emotional and cultural weather vane. In that sense she does matter.

minette.marrin@sunday-times.co.uk

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