Her Royal Highness is turning into her Royal Hairness with that dark, glossy mane.

London - No one can be in doubt that The Duchess of Cambridge has behaved impeccably in her first year of marriage to Prince William.

Middle-class Middleton has crossed the class divide with grace - she’s courteous, elegant and never stops smiling, especially when her beloved husband is at her side.

But is it just me or has something rather strange happened to Kate recently?

It’s not her whittled-down waist. Nor is it her fashion sense, the love of High Street brands such as Reiss and LK Bennett, which earns her brownie points with the public and is turning her into a fashion icon.

No, it’s those famous locks, which seem to be getting longer by the day. Her Royal Highness is turning into her Royal Hairness with that dark, glossy mane.

And I’m wondering if now, a year on from her wedding, it might just be time for the chop.

Now I’m not suggesting for a moment that Kate should be sporting a Mia Farrow crop or middle-aged bob. But the blanket of hair which arrives five minutes before she does has to go.

Recently, Kate was greeting children at a charity event. Dressed in a dark blue tweed skirt and jacket, she looked stylsh, professional and charmed everyone.

Yet every time she bobbed down to talk to one of the youngsters, her face was completely obliterated by a cascade of dark curls. She would flick it out of the way, fondle and fiddle with it and I lost count of the number of times she had to tuck it behind her ear. At one point she looked like Cousin It from the Addams Family - all hair, no person. It was so distracting.

Even Princess Diana realised early on in public life that people wanted to see her face. She cut her droopy bangs and settled for a much more sophisticated short style. It worked, showcasing her enormous blue eyes and strong features.

So why is Kate clinging to her own over-long mane? Even she must have been infuriated by being overshadowed by her hair, because at her very next event she attended at the Imperial War Museum she’d put it in a back-teased half-up, half-down style. But even that style was more WAG than HRH.

For goodness sake, she’s a member of the Royal Household now, not Cheryl Cole. Every time I see her fondling her hair I’m waiting for her to look into the cameras and coo: “Because I’m worth it.”

Kate’s mane has none of the elegance of Mary, the Crown Princess of Denmark, also a young woman of ordinary birth who has risen to the highest position in the land. On Kate and William’s trip to Copenhagen in the autumn, Mary’s shiny, shoulder-length brown hair looked far more elegant than the Duchess’s tumbling curls.

Surely an image-conscious young woman like Kate can’t be oblivious to this?

Yet there are probably a number things stopping her cutting her hair. First there is a long Royal tradition of establishing a look, then keeping it.

The Queen is the perfect example. Apart from the colour, her hair has hardly changed since she took the throne six decades ago. Less successfully, Princess Anne revels in the same unflattering hairstyle (and the same frocks) she wore half a century ago.

It’s widely known that Camilla’s hair-stylers have tried for years to tease her out of the rather dated 1970s Farrah Fawcett flick she’s been sporting since she was a girl. Yet she always responds: “Charles loves my hair this way.”

Men like us to look the same way we did when we met - but letting that dictate your hairstyle is a big mistake. When I married, my hair was halfway down my back. I kept it that way for all the years we were together, but it didn’t save the marriage.

While I’m sure that Kate’s tumbling chestnut locks were one of the things that attracted William to her when they met at St Andrew’s University, they were only one part of it.

Let’s not forget that it was when he saw her sashaying down the catwalk in a see-through black lace dress revealing her knickers and bra that he reportedly exclaimed: “Wow, Kate’s hot!”.

Of course women know that men like long hair. Quite why, I’ll never understand. Is it more feminine? Is it tantalising to have long tresses draped across their body when you make love? Who knows? They just love it. They think it’s sexy and youthful.

But it’s been ten years since Prince William met Kate Middleton and now she’s his wife - she’s bagged her prince and should be secure in his love, regardless of the length of her hair.

And there is a quite delicious irony that as her husband William’s hair recedes - at a frighteningly rapid rate - Kate’s keeps on growing.

Of course there is another obvious reason why Kate may be reluctant to give up her signature style. Subliminally, long hair is a woman’s way of clinging on to her youth. In the past year Kate has reached 30, a milestone for any woman, and married into the royal family, taking on a whole host of responsibilities.

With nights out at Mahiki replaced by evenings at the opera with her new father-in-law, is it any wonder that the Duchess is clinging to her hair as the last vestige of her girlhood?

Perhaps her long hair reminds Kate that at heart she’s a Middleton, the daughter of an air hostess made good, and that remaining down-to-earth - she refuses a butler or maid - is the key to her success. Her hair provides solace and camouflage.

Having had long hair all my life, I can sympathise with these feelings. But there are some truths I know. One is that it isn’t always flattering. There are times when it just becomes ageing, dragging down a face which is no longer plump and youthful.

At 55, model Jerry Hall can just about carry it off, but she is blessed with great beauty. And yes, Kate is still young, but for heaven’s sake she is 30, not 20 - a few inches off the bottom might just bring her hair into 2012.

I speak from experience. A few weeks ago my hairdresser Kerry said he thought it was time for the chop. Not into a short style, but a bit of a freshening up.

So last Sunday he cut four inches off my hair, transforming it into a swishy style which grazes my shoulders - taking a good four years off me in the process.

So I’d urge the girl from Berkshire to be brave. It must be so hard for her to be constantly photographed and scrutinized, but she should be confident.

She is a charming young woman doing a good job with the love and support of a husband who adores her, not to mention the affection of the entire Royal family - unlike Diana.

Come on, Kate. Discard the comfort blanket and let the world see you for the lovely, kind young woman you really are. - Daily Mail