Fans say Princess Charlotte looks just like a young Lady Kitty Spencer, after Princess Diana's niece shared a childhood snap of herself.
Lady Kitty, 27, shared a sweet black-and-white picture of herself on Instagram, which she captioned: "First day of school #tbt", reports the Daily Mail.
The photograph shows young Kitty, believed to be around four-years-old, posing in a gingham dress and black dolly shoes.
Royal watchers quickly pointed out the similarity between her and Charlotte, three - with some saying that they even mistook the picture as being one of the young princess.
One fan commented: "Princess charlotte looks like you!' while another added "I thought it was princess Charlotte for a moment".
Another posted: "Princess Charlotte has the Spencer genes. You look so similar on this."
Meanwhile, others wrote "how much does she look like Charlotte" and "Split image of Charlotte".
In the picture of Kitty on her first day at school, Diana's niece is seen with her hair clipped back - just like Charlotte on her first day of school.
Charlotte is also seen wearing similar-style shoes in burgundy in the snap taken by the Duchess of Cambridge, as the young princess left for her first day at the Willcocks Nursery School in January.
Kitty is the eldest daughter of Earl Spencer, Diana's brother, and his first wife Victoria Lockwood.
She has remained close to Prince William and Prince Harry since Diana's death, attending both their weddings.
The model wowed in a green floral dress by D&G as she attended Harry and Meghan's wedding at Windsor Castle in May.
The comments on the resemblance between Kitty and Charlotte comes after comparisons between the young royal and Diana.
Meanwhile, other fans have remarked on how much Charlotte looks like the Queen in official portraits.