LONDON – Princess Charlotte of Cambridge, fourth in line to inherit the throne of the United Kingdom, turned four years old on Thursday and Kensington Palace released three new photographs to mark the occasion.

Charlotte, the second child of Prince William, Duke of Cambridge, and Catherine, Duchess of Cambridge, were taken by her mother on the grounds of Kensington Palace in the heart of London and at Anmer Hall, the Cambridge’s country home in eastern Norfolk. It is close to Sandringham, Queen Elizabeth II’s home there.

“The Duke and Duchess of Cambridge are very pleased to share three new photographs of Princess Charlotte ahead of her fourth birthday,” Kensington Palace said. “The photographs were taken in April by The Duchess at Kensington Palace and at their home in Norfolk,” a statement added.

Charlotte is the younger sister of Prince George, who turns six in July, and the older sibling to Prince Louis who turned one-year-old just last month.

The princess appears in one photograph, taken at Kensington Palace, wearing a summery floral dress and sporting sneakers with no shoelaces while sitting on the lawn and looking up at the camera.

In another, she wears a plaid skirt, dark navy blue leggings and a wool jumper as she looks pensive while she sits atop a wooden fence at Anmer Hall.

In the final shot, she is wearing the same outfit but is smiling broadly as she runs forward on a lawn holding a small daffodil.

The little girl, whose full name is Charlotte Isabel Diana of Cambridge, was born at the Lindo Wing, the private maternity wing of St Mary’s Hospital in the Paddington neighborhood of London in 2015.

Her mother, Catherine, 37, formerly known as Kate Middleton before her marriage, has become one of the world’s most photographed women and is herself also an avid photographer.

She has often released images taken by herself, as she did to mark Prince Louis’ first birthday on April 23 and for Charlotte’s third birthday, when the little girl was snapped kissing Louis as a newborn baby.

Prince William, Duke of Cambridge, is second in line to inherit the throne and is expected to become king of the UK and 15 other Commonwealth realms, thus making Catherine a likely future queen consort.