Charlotte, who was attending a children’s party in Victoria on day six of the Canadian royal tour, looked adorable in the blue dress, which is sold online for £74.
The handsmocked number features coral embroidered details at the front and matching stitching on the frilled puff sleeves and a Peter Pan collar.
Kate paired her daughter’s dress with a blue knitwear cardigan by another Spanish brand Mi Lucero, Charlotte’s trusty UFO Mary Jane shoes and a sweet bow by Amaia Kids.
This was the second time Charlotte was pictured in a handsmocked dress by the children’s label, the first being when she arrived in Canada on Saturday in a similar blue frock.
Prince George, meanwhile, wore the Harry jumper in blue by Wild & Gorgeous, a brand favoured by Samantha Cameron for her children. The 100 per cent merino wool jumper is sold online for £65.
"We are absolutely delighted that Prince George is wearing Wild and Gorgeous," said co-founder Sophie Worthington. "He looks absolutely adorable in the Harry Jumper."
The three-year-old paired the knitwear with burgundy shorts and navy leather Barnie loafers from Papouelli.
Speaking exclusively to HELLO! Fashion, Pepa & Co's founder Pepa Gonzalez also said: “Both Prince George and Princess Charlotte look adorable in every outfit they have been pictured in, wearing classic and traditional style childrenswear.
“I feel very proud that the Duchess of Cambridge has selected our label, Pepa & Co for her children.”
“To get the royal seal of approval has been an honour for me,” she added.