On Prince William and Duchess Kate's official Instagram page, followers are regularly treated to pictures of the three Cambridge children. And this weekend, the royals shared a sweet new photo of Princess Charlotte.

Princess Charlotte and butterflies

In the picture, Princess Charlotte, 6,  holds a butterfly very delicately in her hands. Kate and William's daughter wears a pretty blue t-shirt, and one thing can't be overlooked in the photo: Charlotte has really grown up!

In May of this year, Charlotte celebrated her 6th birthday. Already then, her birthday portrait showed just how tall she's getting.

But this new picture was posted as part of the Save Butterflies project. With the post, William and Kate wrote: "We wanted to share these beautiful Peacock and Red Admiral butterflies as part of Big #ButterflyCount initiative taking place across the UK."

And the fans are delighted with Princess Charlotte's photo. "Princess Charlotte is getting so big," one fan wrote. "Such a sweet pic of Princess Charlotte," a commenter added, while another wrote, "Beautiful Charlotte and butterflies."