LONDON (CBSNewYork) – A new documentary goes behind the scenes to capture Queen Elizabeth, Britain’s oldest reigning monarch, at work.

It also shows the 92-year-old preparing younger royals for the future, including American Meghan Markle.

Seeing her dress for the first time since her wedding day, the Duchess of Sussex reveals it hid a touch of tradition.

“Did you see it, the piece of blue fabric stitched inside? It’s my ‘something blue.’ It’s fabric from the dress I wore on our first date,” she said.

Her interview appears in the new documentary “Queen of the World,” featuring Queen Elizabeth as head of the Commonwealth, nations once part of the British empire. You’ll see her carrying out her work, in one case recording a Christmas message, only to be interrupted by birds.

“Could you redo that because there were some bird noises outside,” the Queen was asked.

“The whole thing again?” Queen Elizabeth responded, and laughed.

Now, the 92-year-old monarch is passing her duties on to the younger royals, like her grandson Prince Harry.

“If you suddenly bump into her in the corridor, don’t panic. I know you will. We all do,” Harry told a group of visiting scholars.

Meghan has joined her husband at commonwealth engagements, and in the documentary, she says he like the flowers stitched into her wedding veil, representing the 53 Commonwealth countries.

“He was really over the moon,” she said.

“I think it’s the first time we’ve heard from her talking about being a member of the royal family,” said royal correspondent Roya Nikkah. Nikkah says Meghan has also been finding her voice, speaking out for causing by launching anew cookbook called “Together.” It aims to help women affected by a deadly fire at London’s Grenfell Tower last year.

“To see her talking about how important the project was in terms of being diverse and supporting a multicultural community, that speaks to the work she wants to do going forward,” Nikkah said.

With Meghan’s support, the book is already a best seller one day before its release.

The documentary “Queen of the World” debuts Oct. 1 on HBO.