The Duchess of Cambridge will be getting a royal makeover ahead of her NZ visit.  Photo / GettyThe Duchess of Cambridge will be getting a royal makeover ahead of her NZ visit. Photo / Getty

Kate Middleton will be lowering the hemline on her couture day dresses and adding tiaras to her ensemble when she visits New Zealand, in a regal makeover supported by the Queen.

The Queen's personal dresser, Angela Kelly, has been recruited to help the Duchess of Cambridge prepare for her royal visit to Australia and New Zealand in April.

Read more: William and Kate confirm NZ tour

The 32-year-old mother of Prince George, the future king, will be encouraged to wear the tiaras favoured by the Queen and Queen Mother and an aide is being lined up to help with her wardrobe, The Mail on Sunday reported.

Job vacancy: A nanny for George in NZ

Ms Kelly will help Kate select statement jewellery and gemstones from the Queen's personal collection to bring Down Under.

This is part of a deliberate move to shift the Duchess's image from High Street to high end, timeless Royal elegance - without losing her freshness and informality, the British press reported.

Ms Kelly has dressed the Queen for hundreds of overseas tours and engagements over the past 20 years. As personal assistant, adviser and curator to the Monarch, her knowledge of wardrobe protocol is unrivalled.

"Angela has been asked to start selecting jewels ahead of the trip," a Palace source said.

"She knows most of the pieces in the Queen's private collection. Her understanding is crucial because this trip will be about Kate appearing more Royal than ever - you can expect to see a lot more tiaras and the Queen will be watching closely."

It's likely that Kate will require up to four outfits a day for the three-and-a-half- week trip and her clothes need to convey her status as the wife of one heir to the throne and the mother of another.

The Duchess is understood to have already spoken to favoured designers including Alexander McQueen and Alice Temperley, who are designing bespoke gowns and day dresses.

Meanwhile, the frilled, girlish frocks she likes have been outlawed in case they detract from the newly grown-up image she needs to project and also to prevent any wardrobe malfunctions - such as that at Calgary airport in Canada in 2011 when a gust of wind caught the skirt of the Duchess's short yellow dress and flashed her underwear to the world.

The Duke and Duchess of Cambridge will visit NZ in April. Photo / GettyThe Duke and Duchess of Cambridge will visit NZ in April. Photo / Getty

Statement jewels from the Queen's personal collection are being selected for the Duchess to reinforce her sense of majesty, including a diamond and ruby brooch in the form of a hibiscus flower.

It was given to the Queen Mother by the people of the country in 1958 and the Duchess is likely to wear it in the same way that she wore a maple leaf brooch to honour Canadians on her first overseas tour in 2011.

She will also consider taking the Queen's wattle brooch, a yellow and white diamond rendering of wattle flowers, mimosa leaves and tea tree blossom.

The golden wattle is Australia's national flower and the brooch was presented to Her Majesty on her Coronation Tour in 1954

Unlike aristocratic Diana, Kate does not have her own family tiara to wear on formal occasions so the Queen has lent her jewels from her private collection.

She is known to like the youthful Cartier halo tiara - which she wore on her wedding day - and the Queen Mother's favourite tiara, which she wore to a diplomatic reception late last year.

The Mail on Sunday claims Kate has asked her personal hairdresser Amanda Cook Tucker to accompany her to Australia, the same expert that joined the 2012 trip to South-East Asia and the Pacific.

Ms Cook Tucker has recently undergone training in the art of attaching a tiara - so that she can style Kate's hair more formally, the paper reported.

According to the Duchess's spokesman, the couple's entourage will be a similar size to previous tours.

"It's too early to explain what the tour party will be," the spokesman said.

"We are still a long way off from finessing the details for the tour."

Designer David Emanuel, who oversaw the Princess of Wales's wardrobe on four big overseas tours, told The Mail on Sunday: "Kate is going to need someone to help her get ready.

"We take for granted how good she looks but it's a lot of work. You need to think about the national colours of the country, its flag and emblems and how to reflect that in the clothes you wear.

"It takes weeks of research and Kate is going to need quality couture for the trip.

"She will be travelling in a warm climate and she will need quality-cut clothes. She really needs a full-time member of staff to help with her wardrobe."

"It's not just the frock, it's the whole thing - shoes, clutch, accessories. A superstar would take an entire personal entourage to look after them. There's no room for a fashion faux pas."

At nine months old, Prince George will be the same age as his father Prince William was when he was first taken overseas by his parents.

Any picture of the family relaxing together will be instantly compared to the iconic southern hemisphere images of Diana playing with William on the lawn of Government House in Auckland, New Zealand, in 1983.

Prince Charles, Princess Diana and Prince William on the front lawn of Government House, Auckland, 1983. Photo / New Zealand Woman's WeeklyPrince Charles, Princess Diana and Prince William on the front lawn of Government House, Auckland, 1983. Photo / New Zealand Woman's Weekly

It was, recalls Royal biographer Sarah Bradford, the trip that catapulted Diana into the limelight: "Diana was amazed by her popularity and the interest in her.

"The Queen has a strong relationship with Australia and New Zealand, and by sending the Duke and Duchess she is projecting an image of the future."