At the age of 87 I find myself not just a first-time author, but a bestseller. I’ve always told stories, but I never thought of writing them down until this past year. Once I got going I found I couldn’t stop, and Lady In Waiting: My Extraordinary Life in the Shadow of the Crown is the result. I’ve enjoyed promoting it as well. Seven decades ago I was a travelling salesman for my mother, who had started a pottery at Holkham Hall in north Norfolk. Off I used to go in my Mini Minor, staying in rundown hotels with all these travelling salesmen. I was the only woman and certainly the only aristocrat on the road. It was rather fun. There was rationing then and in the evenings we used to all sit in a dismal lounge with one bare lightbulb and the trolley would come round and the travelling salesmen would say: ‘Will you be mother?’

What everyone seems to want to know about is the royal family, especially the coronation and my years as lady-in-waiting to the wonderful Princess Margaret. When I was growing up at Holkham, the princesses used to come over to play. Princess Margaret was more my age and we became great friends. There’s a rather nice photograph of Princess Margaret looking at my feet. One day just before she died I found the photograph and asked her why she was looking at my feet and she said: ‘Well, Anne, you had silver shoes, and I was so jealous because I only had brown ones.’

During the war a lot of children of our background were evacuated to Canada and America. People were expecting the Germans to land on the Norfolk coast so my sister and I were sent up to Scotland. I remember we felt very proud that we were in Great Britain and so were Princess Margaret and Princess Elizabeth. We were simply thrilled when Princess Elizabeth talked to the children of Great Britain and Princess Margaret came on at the end to say: ‘Goodnight children everywhere.’ We thought they must be actually in the wireless, or behind it or something.

By far the most fun interview I’ve done to promote the book was going on Graham Norton’s red sofa. I liked him so much. I was on with Olivia Colman and Helena Bonham Carter, who are now playing the Queen and Princess Margaret in The Crown. I knew Helena as she was a cousin of my late husband Colin Tennant, and I knew that Olivia came from Norfolk and went to school here, so we had lots to talk about. Loose Women was another highlight. Janet Street-Porter was one of the presenters and she told me she had been to St Lucia and had met Colin twice, and also our elephant.

The publicity tour is starting to wind down now, though I did just do an interview for a new programme about the royal family at war. I was only seven when the war broke out, but I went to a school just outside London for the last two years of the war and we got all the doodlebugs. Not that my parents were very worried about it. We just slept in the cellars. The school was freezing, just like it always was at Holkham. The television people got talking about what they call ‘snowflakes’ nowadays — young people who just won’t put up with anything. I’m afraid I have got no patience for it. I have great-grandchildren now and luckily they’re brought up sensibly, not to complain and certainly not to be glued to their iPads or whatever they are. They put them away and we always have proper meals around the kitchen table. They learn how to cook too.

The family’s all coming for New Year. But I’m spending Christmas very quietly this year with my darling nanny, Barbara Barnes — who looked after my children and then went on to look after Princes William and Harry. She’s very much part of our family. Christmas at Holkham was always magical. There used to be a huge Christmas tree in the long gallery all lit up by real candles. And we each had our own card table, which people put our presents on. There was a party for all the children on the estate a few days before so they could see the tree and we’d have a lovely tea.

We used to go to Buckingham Palace too, because my father was an equerry to the Duke of York before the Duke became King and the princesses used to have Christmas parties there. When we left there was a big table full of presents and I remember Queen Mary was standing behind it — absolutely terrifying actually — and my younger sister rushed forward and grabbed this huge teddy bear. I remember that I saw a doll I rather fancied and as I stretched out my hand Queen Mary said: ‘Anne, I would like to give you a piece of advice. Quite often better things come in little boxes.’ I didn’t want to take a little box at all, but I rather felt I had to with Queen Mary glaring at me, and so I did and she was quite right. I got a pearl and coral necklace which my great-granddaughter Ruby is going to wear this Christmas.