The Duke and Duchess of Cambridge released a photo of their daughter Princess Charlotte ahead of her sixth birthday on Sunday.

The photo of the royal couple’s second child and only girl was taken by her mother, Kate Middleton, who is a prolific photographer, in Norfolk.

Charlotte flashes her pearly whites in the sweet photo as she enjoys the outdoors in a pretty pink and blue floral summer dress. 

Recent but undated handout photo issued on Saturday May 1, 2021 by Kensington Palace of Princess Charlotte. The image was taken by Kate, Duchess of Cambridge in Norfolk, England ahead of Princess Charlotte's sixth birthday on Sunday. (Kate, Duchess of Cambridge via AP)

Recent but undated handout photo issued on Saturday May 1, 2021 by Kensington Palace of Princess Charlotte. The image was taken by Kate, Duchess of Cambridge in Norfolk, England ahead of Princess Charlotte's sixth birthday on Sunday. (Kate, Duchess of Cambridge via AP)

Many Twitter users noted the girl's resemblance to her father. 

Others noticed how much she looks like her late grandmother Princess Diana.

The duchess and Prince William also celebrated their tenth wedding anniversary last week.  

In this photo provided by Camera Press and released Wednesday, April 28, 2021, is Britain's Prince William and Kate, Duchess of Cambridge, at Kensington Palace photographed this week in London, England. The Duke and Duchess of Cambridge celebrate their tenth wedding anniversary on Thursday, April 29. (Chris Floyd/Camera Press/PA via AP)

In this photo provided by Camera Press and released Wednesday, April 28, 2021, is Britain's Prince William and Kate, Duchess of Cambridge, at Kensington Palace photographed this week in London, England. The Duke and Duchess of Cambridge celebrate their tenth wedding anniversary on Thursday, April 29. (Chris Floyd/Camera Press/PA via AP)

William and Kate also have two boys: Prince George, 7, and Prince Louis, 3.

The couple released a cute snap of Louis on a bicycle for his third birthday on April 23. The picture was taken before his first day of nursery school.

In this handout photo provided by the Duchess of Cambridge, Britain's Prince Louis smiles before his first day of attending Willcocks Nursery School, at Kensington Palace in London, Wednesday, April 21, 2021. Prince Louis turns three years old on Friday April 23. (Duchess of Cambridge via AP)

In this handout photo provided by the Duchess of Cambridge, Britain's Prince Louis smiles before his first day of attending Willcocks Nursery School, at Kensington Palace in London, Wednesday, April 21, 2021. Prince Louis turns three years old on Friday April 23. (Duchess of Cambridge via AP)

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The family will likely be at Anmer Hall at Queen Elizabeth's Sandringham in Norfolk this weekend because Monday is a public holiday in the U.K, according to People magazine.

The Associated Press contributed to this report.