At 30, Kate Tiptoes into The Royal Limelight

The Duchess of Cambridge will celebrate her 30th birthday on Monday with a "low-key and private" event, an official at St James's Palace says.

Catherine has reached the milestone after a tumultuous year that has seen her marry Prince William, embark on her first official overseas tour and take on several commitments to voluntary work.

But staff at the couple's official residence discounted reports that Prince Harry and Catherine's younger sister Pippa were planning a big party.

"Whatever is planned will be low-key and private," St James's Palace said.

It is thought Catherine will spend her birthday with William and close family and friends.

William, an RAF search and rescue helicopter co-pilot, is rostered to work this week from his base at RAF Valley in Anglesey.

On Sunday night, William and Kate kicked off the celebrations at a glamorous black tie premiere of War Horse in London's Leicester Square.

Michael Morpurgo, the author of the book that inspired the film, led the birthday wishes and said he would send her a copy of the novel as a gift.

Turning 30 will cap a life-changing 12 months for the new royal, who married her fiance on April 29 last year in a glittering Westminster Abbey ceremony in front of a television audience of billions.

After honeymooning in the Seychelles, the newlyweds toured Canada and California last summer, where they received a rapturous welcome.

Last week it was announced the Duchess has agreed to support four organisations, two as patron - Action on Addiction and the National Portrait Gallery - and East Anglia's Children's Hospices and The Art Room as royal patron.

The Duchess will also become a volunteer with the Scout Association, joining activities privately with groups in north Wales and other areas in a post known as an occasional helper.

As she enters her fourth decade, the former commoner Kate Middleton has already become a "global superstar," according to seasoned royal watcher Ingrid Seward.

She "hasn't put a foot wrong" and "what's more, she has made it all look so easy," Seward wrote in the Sunday Express.

Catherine's wedding to the second-in-line to the throne last April was watched by an estimated two billion TV viewers.

Her face has adorned millions of magazine covers and every one of her outfits is pored over, with the clothes invariably becoming instant best-sellers -- as was the case for William's mother Diana.

Meanwhile, celebrity magazines scrutinize every photograph for evidence of a baby bump, but she is not pregnant yet, and the pressure will inevitably build from a hungry media as time goes on.

Catherine lives far from the bright lights and long lenses of London with William in Anglesey.

As BBC royal correspondent Peter Hunt said: "She is, like Prince William, still tiptoeing towards her destiny."

Since the wedding, she has performed just 15 or so official engagements in Britain and a tour with William of Canada and California -- a tiny number of appearances compared to other members of the royal family.

If she is rarely seen, she is heard even less. Catherine does not, yet, make speeches.

Yet she enjoys huge popularity and those members of the public who have met her report that she is happy to chat and that the daughter of a former pilot and flight assistant is without airs and graces.

When she made her first appearance with the royal family at their traditional Christmas Day church service, there was no doubt that Catherine, in a plum-cultured coat and hat, was the one the crowd had come to see.

This month, following royal tradition, she announced which charities she will support, and made a commitment to become a volunteer scout leader, mainly near to her Anglesey base.

She will be associated with just four charities -- the queen is patron of 600. Catherine will link up with a group which helps wayward children through art and a charity helping former drug addicts to put their lives back on track.

She has ever so gradually started to follow the path of William's late mother Diana, who championed the plight of AIDS patients and landmine victims among many causes.

In a barbed comment on Catherine's charity commitments, The Independent said it was "an arrangement to suit everyone".

"The charities get cash and visibility. The princess gains a public persona -- much-needed, as it happens, since there has been a growing sense over the past few months, that, beyond the trim figure and the pearly-toothed smile, the new member of the royal family is ever so slightly dull."

Yet such digs are rare, and as she turns 30 Catherine enjoys an overwhelmingly positive press, with newspapers also perhaps treading carefully after their ceaseless pursuit of Diana.

Robert Jobson, the author of "William and Kate: The Love Story," told Agence France Presse that she should resist pressure to change the personality that first attracted William when they were students together at university in Scotland.

"Everyone's got great expectations but it's important for Kate, if she's going to be accepted and popular, to be herself," he said.

"You can't be a media-managed perfect princess, there is no such thing, you can't create the image of a princess on a computer screen and make it absolutely how it has to be.

"You have to take risks; you have to show your personality. At present, she hasn't really had the opportunity to do that."