Shortbread is not normally a source of sibling tension.

Nor is it an internationally-recognised sign of complacency but, with her son closing in on a historic first Wimbledon title, Judy Murray's mind was on biscuits.

"I remember my brother getting this tin of shortbread out at the end of the second set and starting to pass it round," she said.

"My mum's famous for her shortbread but I was so angry with him because you never relax until the last ball is hit and I felt he thought Andy had got it in the bag."

No one knew better than Judy by July 7 2013 that absolutely nothing should be taken for granted when it came to Andy and grand slam finals.

Twelve months earlier she had watched on from almost the same spot as he took the lead against Roger Federer only to lose in four sets and then sob his way through an on-court speech.

She had also been in New York in September 2012 when Andy appeared on course to ease to a first grand slam title as he led Novak Djokovic by two sets to love at the US Open.

But back came Djokovic to level the match and, by the time Andy finally clinched victory in the fifth set after six minutes short of five hours, all in the Murray camp were so emotionally spent that a glorious numbness was all they had left.

Now here was Andy again, one set away from becoming the first British man in 77 years to win one of the holy grails of sport.

Djokovic took the lead in the third set, as he had in the second, but back roared Andy and suddenly he was serving for the match.

"Normally when I watch him I can remember the sequence of the match, the big points and notable things that happened but I can't remember anything about that match apart from the final game," said Judy.

And what a final game it was - 12 minutes of torture.

"At 40-0 I remember being able to hear my heart beating. I thought it was just one good point, one big serve that doesn't come back," she said.

"But then it was deuce and Djokovic had a break point. I remember Djokovic had a net cord at one point and I swore under my breath.

"Some of his supporters were sitting across the aisle from me, literally no more than arm's length away.

"One of them was like a Serbian Buster Bloodvessel. He was getting really noisy and pumping his fist and I was determined not to take any notice because I knew he was just trying to wind me up.

"The whole thing is an absolute blur. I'm surprised I'm still alive."

Having saved three break points, an explosion of noise greeted the moment of victory when Djokovic netted a backhand.

The new champion himself let out a long yell of delight and pumped his fists, celebrating with the crowd before making the customary climb up to join his supporters.

He would have missed Judy, who was sitting behind the player box, but for the cries of 15,000 people urging him not to forget his mum.

Andy turned back for a brief hug - not that Judy minded either way.

"I wasn't bothered at all," she said. "I was more concerned that he was going to fall through the flimsy roof he was standing on."

Plenty of accolades have come Andy's way since that scorching day in July - BBC Sports Personality of the Year, an honorary degree and freedom of the city of Stirling among them - and perhaps a knighthood will follow at some point.

But for Judy it is the effect Andy and his brother Jamie, a Wimbledon champion in mixed doubles, have had on children in Scotland that pleases her most.

"Where I feel it the most is when I go to the tennis club in Dunblane where Andy and Jamie played when they were just little boys who enjoyed the game," said Judy, who also provides guidance to up-and-coming young players through her role as a HEAD ambassador.

"It's just a four-court club in a small town in a country where tennis is very much a minority sport, the facilities are limited and the weather's terrible.

"What they've managed to achieve, when I see all the kids out on the courts, I just think it shows that you never know where they're going to end up.

"Anything is possible if you have a talent and the opportunity to fulfil it."