Kate Middleton answers girl's adorable question about 'Princess Elsa' dress

The Duchess of Cambridge has been left to explain to a royal fan why she wasn't wearing a Princess Elsa dress.

Kate, 37, joined Prince William for a visit to Cumbria on Tuesday.

Two shy sisters handed flowers to the royal, according to PEOPLE, and interacted with Kate through their dad.

"It's a princess. You love princesses!" the dad reportedly told his girls as they shook hands with the Duchess.

He then asked Kate a question on one of his daughter's behalf.

"She wanted to know if you'd be wearing your Princess Elsa dress," he said, referring to the character from Disney's Frozen.

"I know. I'm sorry," Kate responded. "I came in my trousers and my coat because I'm going to see some sheep."

Kate then complimented the girls on their French braid pigtails, telling them their hair looked "so pretty".

She confessed to having tried and failed to plait her own daughter's hair.

"I tried to do a plait with Charlotte this morning, and it didn't really work very well," she reportedly said.

Royal fan Helen Jones met the Duchess and spoke to her about the Cambridge children.

"She said Charlotte was looking forward to school," the woman said. "She was very friendly."