Kate Middleton and Prince William will release new photos of their 1-month-old daughter, Princess Charlotte, and big brother Prince George on Saturday, June 6 Credit: Anwar Hussein/WireImage

Let the countdown begin! Kate Middleton and Prince William are set to release new photos of their daughter, Princess Charlotte, on Saturday, June 6. A sneak peek of the official royal family photos, which also includes her big brother, 22-month-old Prince George, was posted at 4 p.m. UK local time.

"We'll be posting a very special photo of Prince George & his little sister Princess Charlotte late tonight," Kensington Palace's official Twitter account tweeted Saturday. "Can't wait to share it with you!" This marks the first time Kensington Palace has released such an important photo on social media.

The photos were taken by Duchess Kate herself in mid-May, a source tells Us Weekly. Kensington Palace will share the first gorgeous snapshot at 9 p.m. UK local time (4 p.m. ET) on their social media accounts, with the rest released at 10 p.m. UK time (5 p.m. ET).

Duchess Kate and Prince William welcomed their baby girl at St. Mary's Hospital in Paddington, London on May 2. Since her debut, they've continued to receive an overwhelming amount of letters and gifts.

"The Duke & Duchess are very grateful for the wonderful messages they've received on the birth of Princess Charlotte," Kensington Palace shared via Twitter. "Mail sacks with congratulations & warm wishes from across the globe arrived at St James's Palace shortly after Princess Charlotte's arrival."

Her Royal Highness, Princess of Cambridge, also received handwritten cards (so much pink!) and handmade stuffed animals from schoolchildren and the UK charity Girlguiding.

Following Prince Charlotte's new photos Saturday, she will next be seen at her christening at St. Mary Magdalene Church in Sandringham on Sunday, July 5.

To see more new photos of Princess Charlotte and Prince George, head back to Us Weekly at 5 p.m. ET.

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