Kate Middleton and Meghan Markle
Kate Middleton lacks this "queen quality" present in her sister-in-law Meghan Markle. Pictured: Middleton and Markle react as they sit in the Royal box on Centre Court to watch Serbia's Novak Djokovic play against Spain's Rafael Nadal during the continuation of their men's singles semi-final match on the twelfth day of the 2018 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, southwest London, on July 14, 2018. Getty Images/Oli Scarff

Kate Middleton lacks a certain "queen" quality that her sister-in-law Meghan Markle has, according to one expert.

The Duchess of Cambridge will be queen consort when Prince William takes over the throne. However, a royal expert believes that Middleton should follow the the Duchess of Sussex's footsteps and speak more.

"As modern women, we can’t have the Duchess of Cambridge or Sussex being these princesses who are seen and not heard," Camilla Tominey said on Yahoo's "The Royal Box" (as quoted by Daily Star). "Meghan’s put herself out there and I've been arguing this about Kate."

"I've got huge respect for the Duchess of Cambridge, but she needs to speak more," Tominey continued. "This has been an issue because she’s afraid of public speaking. It doesn’t come naturally to her."

To help Middleton conquer this, Tominey shared some suggestions. "What they need to do, in my personal opinion, is to get her confidence up and get her in a position where she’s speaking with more confidence," she said.

Tominey added that although it is unnatural for Middleton, this is "really important" for her considering that she's the future queen. "We need her to be on a world stage," she added. "Kate’s got a great deal to offer on her own terms, not just as Prince William’s wife."

A number of experts agree that Markle is better in public speaking compared to Middleton. In fact, body language expert Judi James compared the two duchesses' first speech and pointed out how shy the Duchess of Cambridge was when she did it.

"I don't know if you saw Kate Middleton's first speech that she made, but she was painfully shy. I think it was to children, you could see that she'd had training, she'd been told to pause. She hadn't taken control of the situation, she hadn't decided to be herself," James explained.

On the other hand, public speaking is so easy with Markle which isn't surprising considering her previous profession. In fact, the former "Suits" star delivered her first royal speech without notes when she launched a cookbook for Grenfell Tower victims in September.

"Working on this project for the past nine months has been a tremendous labor of love," Markle said. "I just recently moved to London and I felt so immediately embraced by this kitchen — your warmth and kindness, and also to be able to be in this city and to see in this one small room how multicultural it was."