Kate Middleton becoming Princess of Wales will be 'bittersweet' for Prince William

While Prince William will eventually become king, Prince Charles will have to decide to bestow his son with the title of Prince of Wales before being crowned.

Consequently, the move will see Kate Middleton become the Princess of Wales, a title which is currently held by Camilla Parker-Bowles.

A source told the Telegraph that the transition is said to be a bittersweet moment as Prince William’s late mother Princess Diana formerly held the title Princess of Wales.

"I’m sure it’ll be a bit of a bittersweet moment," the source said. 

"This is her [Diana’s] son and his wife, so in some ways it will be coming full circle—but it will also be a poignant reminder of what we all lost."

Furthermore body language expert Darren Stanton previously told Marie Claire that the Duchess of Cambridge seems to be ready for the big change to become queen. 

"She is always seen with a very open and honest smile denoted by visible crow’s feet around her eyes," he said.

"Her whole face is engaged when smiling and it’s clear she has developed a massive confidence not only as a royal and a public figure, but as a parent too.