AFTER celebrating her 80th birthday and getting used to a new knee, you might think Mary Berry would want to sit down and put her feet up with a slice of her famous lemon drizzle cake. But there is no time for that. There is a multi-million pound store to open, books to sign and a Q&A with fans queuing up for a quick fix to a ‘soggy bottom’.

Mary may have turned 80 this week and had a knee replacement in January, but she will be “rushing about” as usual this Saturday promoting her book (Mary Berry’s Absolute Favourites) and opening the swanky new £4.5m Barker and Stonehouse store at Teesside Park, in Stockton. Complete with two floors of retail space, a cafe and roof garden, the store is celebrating a return to its roots as it was Stockton where the first branch opened in 1946. It is now the UK’s largest independent family-run furniture retailer.

Mary has already been tempted by some tartan cushions and a light made out of antlers. “When you get to my time of life you’ve got most things for your home, but I thought their sofas were lovely,” she says. “They have some very famous names, for example, Ercol, which is made in High Wycombe where I come from. Mr Ercolani, in fact, used to live in our village.”

It is not the first time Mary has been to the North East. She has been to Eggleston Hall. the former cookery school near Barnard Castle, many times. “I think the countryside is beautiful,” she says.

Aside from her role as judge on BBC TV’s The Great British Bake Off which is watched by millions, Mary has published more than 70 cookery books, the first being The Hamlyn All Colour Cookbook in 1970. In 2012, Mary was awarded a CBE and in 2014, hosted her own show, Mary Berry Cooks.

As well as the ‘Queen of Cakes’, Mary has also become a fashion icon, with her colourful jackets and fresh style. She was in The Guardian’s 50 best dressed over 50 list and the floral bomber jacket (£29.99 from Zara) she wore while filming, sold out nationwide.

“I don’t spend a lot on clothes. I get them from the High Street usually and they have got to be nice and warm and cheerful,” she says. “I hope I dress for my age and I like clothes that I hope suit me because even though you’re a more mature woman. you can be cheerful.”

Although she struggled with her weight as a teenager, Mary keeps trim with a good balanced diet and “not too many second helpings”.

“Obviously when I’m judging, I have to taste everything and I love doing it. so around Bake Off, I keep to light food,” she says.

So if she had had the opportunity to be a contestant on The Great British Bake Off when she was starting out, would she have done it? “I wouldn’t have wanted to do it,” she says. “I’m not that competitive.”

Is there a cake or dish she still has to perfect? “I don’t think so,” she says. “I cook things my family enjoy. I think any busy mum has disasters because they are trying to do too many things at once. If I burn a cake – and it can happen to all of us – I would just make it into a trifle or something.”

Mary grew up in Bath – her great great grandfather was a master baker in the 1860s – and cookery was the only subject she enjoyed at school. At 13, she contracted polio and was in hospital for three months. It left her with a twisted spine and weaker left hand (which prompted one Bake Off viewer to write in with a remedy for arthritis). It was an experience which “toughened her up” and taught her to make the most of every opportunity.

Mary’s first job was working for the electricity board showroom in Bath when she would visit people at home and demonstrate the ovens by making a Victoria sponge. At 22 she applied to work at the Dutch Dairy Bureau, before moving to France to train at The Cordon Bleu school in Paris. Mary later became cookery editor of Housewife magazine and Ideal Home and was amongst the first generation of women to juggle a family and a career.

Now a grandmother, Mary had three children of her own, but suffered tragedy when her son, William, was killed in a car crash at the age of 19. It took a long time for her to return to cooking, but when she did, she found it physical and mental therapy.

In the early Seventies, she starred in her first TV series, Afternoon Plus, with Judith Chalmers which was a huge success and in the 1990s, she launched a cookery school at home attracted more than 12,000 visitors over 16 years. Mary has also appeared on The One Show, Food and Drink Programme, Graham Norton Show and Loose Women.

Despite the pressure on female TV presenters today, Mary says she would never have considered Botox, even if it had been popular 30 years ago. “I don’t believe in any of that,” she says. “Whether I’m younger or older, I wouldn’t consider it. Can’t be bothered. I don’t think there is any need to do it. Leave the wrinkles to come. I think they’re character.”

Her mission is ‘to get everyone baking’, which has won her fans across the nation. She can barely step outside without someone tapping her on the shoulder to tell her they have baked her lemon drizzle cake. “People are very nice,” she says. “Children send me all sorts of buns and seem to make their own birthday cakes now.”

As for her own birthday, will Mary be baking her own cake?

“No,” she laughs. “I won’t be baking my own cake. Lucy and Lucinda [her assistants] will be concocting something. I like lemon flavour best, but I’m quite easy.”

* Mary Berry will be opening the new Barker and Stonehouse store and a Q&A session at Teesside Park, Stockton on Saturday (March 28).