Kate Middleton 'guides' the royal family, according to Prince William's former private secretary

• Kate Middleton became the Princess of Wales after Queen Elizabeth II's death.
• She is a "matriarch" for the royal family, Prince William's former private secretary told People.

Following Queen Elizabeth II's death, roles in the royal family shifted.

King Charles III became the monarch, and he made Prince William the Prince of Wales and Kate Middleton the Princess of Wales.

But the loss of the Queen also left a leadership gap in the monarchy, as the late royal was not only a steadying force for the United Kingdom but also for her family.

And according to a former royal staffer, Kate Middleton is stepping in to fill that role.

"She is a matriarch," Prince William's former private secretary Jamie Lowther-Pinkerton told People of Kate's role in the royal family.

"Not in the sense of an older woman in a twin set and pearls, but she guides the family," Lowther-Pinkerton went on to say to People.

Lowther-Pinkerton also said the Princess of Wales "advises" William when he wants her to, much like Camilla, Queen Consort, does for King Charles.

In an excerpt of royal reporter Kate Nicholl's upcoming book, "The New Royals: Queen Elizabeth's Legacy and the Future of the Crown," published in The Mail on Sunday, Nicholl wrote that the king practices his speeches for Camilla and speaks to her about his ideas and that there are "times when she calls the shots."