Her every move, her every dress and her every hairstyle is certain to be scrutinised, studied and copied across the globe. Welcome to life as a princess in the 21st century. One retail expert has already estimated that the new princess will be worth in the region of £150 million ($290 million) a year to the economy - mainly as a benefit to the fashion and beauty industry. Before she is even 10, she will be worth £1 billion ($1.92 billion). Meet the princess: The eyes of the world will constantly be on the new royal. Credit:WPA Pool Penny Junor, royal author and biographer of both Princes William and Harry, said the arrival of a girl added a "new dimension" to the male dominated royal family. "She is going to add a whole new layer of interest to the royal family. She is going to bring so much glamour," said Ms Junor. "We have seen boys growing up as princes but there's nothing like a little girl. It adds a whole new dimension. Princesses wear beautiful clothes. They endear themselves in a way boys don't. We have not had a princess growing up at the heart of the Royal family for such a long time.

"Not many people will remember Princess Anne growing up. It was a totally different age. And anyway Anne was never very interested in fashion." Kate and William leave hospital. Credit:Chris Jackson Miss Junor said the new princess needed to be protected from the media intrusion and inevitable scrutiny that will come with every new outfit and hairstyle. "The thing that worries me is she will be pulled apart," said Miss Junor. "Constantly people will ask what her hair is like, has she put on weight. It will be hard being a teenage princess." Kate Middleton and Prince William present their new daughter.

The little baby's older brother, Prince George, is already subject to constant attention. While the British press have an agreement with the Duke and Duchess only to publish authorised photographs of the prince, foreign paparazzi play by no such rules. Only last month, sneaked pictures were published abroad of Prince George enjoying a day out at a local park; no such photographs appeared in the British media but the images abound on the internet. There's nothing like a little girl. It adds a whole new dimension A princess growing up through the years is bound to attract just as much - if not more - attention. Christopher Wilson, a royal historian, said that Princess Margaret, born in 1930, was the last great glamorous princess born into the Royal family. "At the time she was dashingly beautiful, but she should also serve as a warning," he said. "After all, look what happened to her."

Mr Wilson said it was key the new princess should be protected. "It will be much more difficult in some ways for a girl rather than a boy," he said. While royal princes can go into the military that, suggested Mr Wilson, would not be a career path open to the new princess. "Nobody thinks about the career structure for the second child," he said. "They will really need to think hard about her career." Ms Junor disagreed. There was no reason, she said, that the new princess couldn't enter the military too. It offered an oddly protective environment from prying eyes - just as it did for princes William and Harry. "In this age of equality, it is perfectly possible she might go into the military," said Ms Junor. "There are some amazingly beautiful girls who do join the military. It would not be beyond the bounds of possibility.

"It has been shown over the years that for senior members of the Royal family it is the one form of employment that doesn't open them up to criticism. The military is a safe option." The fashion industry, doubtless, will hope she opts for a less macho career. Lisa Armstrong, the London Telegraph's fashion editor, suggested the baby princess would act as a model for young mums looking to dress their children. "What Kate is very good at is showing how every woman can look very nice in a non-threatening way," she said. "The way Kate dresses the princess is bound to be very traditional and very demure and that will be really nice to see after years seeing little girls running around in spangly pink halter neck type tops." All eyes for the next two to three decades will be on the baby and how she is transformed into a young lady.

Loading The baby princess, of course, won't have a clue about what awaits her. But she will grow up to be the most famous princess in the world. And regardless of the outcome, every little girl starts out in life wanting that. The Sunday Telegraph, London