She said: “I was told that Her Majesty would be coming through the door at the top of the picture gallery to chat at midday.
“So no pressure of course, having never built this cake before.”
The magnificent wedding cake was constructed using 17 individual fruit cakes, weighed over 220 pounds and had around 900 individually iced flowers.
It was also a first for the Royal Family as it was the first cake prepared for a royal wedding to be stacked rather than use pillars for support.
It also strayed from tradition by using soft icing rather than the typical harder kind.
“When the Queen came to see us, the cake wasn’t completely finished,” said Ms Cairns.
“I can remember her saying ‘I hear that you’ve been dismantling my house.’
The Cambridges’ royal wedding back in 2011 was viewed by tens of millions around the world, with around 72 million live stream views on YouTube.