In the final episode of the series she described life after her operation, adding: “You’ve got an enormous scar, but you like yourself…. You’ve got a badge of office, you just are what you are, and… of course the last thing that the Queen said to me [was]: ‘Just be yourself Sarah’.

“And she saw it. She just got so annoyed when I wasn’t being myself. And that’s probably when I got into all the pickles. But now I am myself and I’m just so lucky to be able to be myself.”

She said the luckiest thing that ever happened to her was having a “wonderful” sister who forced her to go for a mammogram which she believes saved her life.

Speaking about Derek, the name she has given to her reconstructed breast, the Duchess said he was doing “very well” and she has started returning to a more active lifestyle, including walking while she was in Scotland to help to keep in shape because “[at] 63 you do need to exercise”. 

The Duchess also said she was the “luckiest person alive” because she had “lived every girl’s dream and become a princess. 

“And I’m there and I’m still there and I still pinch myself and I still can’t believe that I’ve come at 63 to be in this extraordinarily lucky place.”

During the 37-minute episode the Duchess also recalled meeting Prince Andrew when she was invited to Ascot by her “best friend” Princess Diana. 

She said was scared her makeshift dress was going to fall apart when the prince teased her that it would be “rude” if she didn’t eat an eclair. 

The grandmother also dispelled two royal rumours, claiming it was “rubbish” Diana was interested in Andrew and had pictures of him on her wall.

But, she said, “Diana really always got on very well with him and I say that he’s certainly the best looking prince.”

She also said it was “rubbish” her father had asked Diana’s mother to marry him.