LONDON (AFP) - A small Spanish fashion label has been swamped with demand for Princess Charlotte's floral dress, its owner told AFP on Friday (Dec 4), after the British royal baby was pictured wearing one of its frocks.

Charlotte, the second child of Prince William and his wife Kate turned six months old on Nov 2 and Kensington Palace has issued fresh photographs of the youngster, taken in early November, to mark the occasion.

The pictures, released on Sunday, show the princess, who is fourth in line to the throne, sitting in a chair and playing with a teddy bear.

The pictures were taken by her mother Kate, the Duchess of Cambridge.

"We don't know how she got the dress," said Ms Margarita Pato Cid, the owner of M&H, a family boutique brand which has been running for six years and has five outlets in Spain.

"We found out that Princess Charlotte was wearing it at the same time as the public, through the photos.

"We think it's possible, but we're not sure, that it's thanks to the nanny of William and Kate's children," she said, referring to Ms Maria Teresa Turrion, who is Spanish and looks after Charlotte and her two-year-old brother Prince George.

The princess has previously been seen dressed in Spanish label clothes.

The dress, which costs €29.95 (S$45.50), sold out in quick time after the Charlotte pictures were published.

The brand, which is not sold online, now has a lengthy waiting list for the dress, mainly from British and United States customers, its owner said.

"We intend to fulfil every possible request. We have some dresses in the making but we don't have enough material to meet all the demands," she said, without revealing the volume of requests.

"It is a great honour for us," she added.

Princess Charlotte Elizabeth Diana of Cambridge was born on May 2, only the fourth baby born with the title of British princess since the start of World War II.

New laws mean she cannot be overtaken in the line of succession by any younger brothers.