What had dropped through the letterbox at her parents' home in Scotland was a formal request for her to be a guest at a lunch honouring some of the most highly-regarded people of the Millennium.
The invitation, bearing theseal of the Corporation of London, was from the Lord Mayor of London, for lunch at Mansion House - the Georgian palace in the City that serves as the Mayor's official residence. The Queen would be the guest of honour.
Yesterday Ms McCrae took her place still slightly bemused about why she was there but happy enough to be among the swirl of celebrities and grandees. From the world of politics there were Lady Thatcher, Sir Edward Heath and John Major, representing sport Sir Bobby Charlton and from the arts Sir Nigel Hawthorne.
The idea behind yesterday's Millenium lunch, in the presence of the Queen and the Duke of Edinburgh, was to recognise the efforts of more than 400 people from the world of music, politics, media and public service.
The Lord Mayor's staff received almost 1,800 nominations from across the country, organised by county councils, Lord Lieutenants and a selection of official bodies. The list was whittled down to 400 invitations and a little over 300 said yes.
"There will be those who will say [today's lunch] is a self-congratulatory exercise and to them I say you are right," the Lord Mayor, Lord Levene, told guests yesterday as they sat down in the Egyptian Hall where the afternoon sun spilled through a stained-glass window.
"By hosting this lunch today the City (of London) is recognising not only what all of you have achieved. For by recognising your achievements we celebrate the achievement of all who have, through their own individual efforts and sacrifices, made this country what it is today."
At first glance the achievements of 26-year-old Ms McCrae have been at a more personal level. On the guest list she comes under the world of sport and is described as a medal winner at the Transplant Games. Between the ages of 11-15 she took part in five Transplant Games where she won medals for several events ranging from Wellington boot throwing to the 100m sprint.
With her athletics career behind her she currently works in the Job Centre in Castle Douglas, Kirkcudbrightshire, and is a keen member of the local Young Farmers.
But her real achievement has been to lead a normal life despite having suffered renal failure at the age of eight and having been on dialysis for the past 10 years. In that sense she is a real inspiration for other sufferers.
"I was eight when I started on dialysis and then I got a transplant that worked for six years. Since the age of 14, I have been on dialysis three times a week," she said.
"I am not sure why I was nominated. The celebrity from our part of the world is David Coulthard (the racing driver). I don't think I have done anything special - I just try and get on with my life."
The anonymous lady from Ms McCrae's home village of Auchencairn, who nominated her clearly thought differently - as did the panel who produced the final list. "This lunch is not just about well-known faces," said a spokes-man for the Corporation of London. "It is about people who have done something to make Britain what it is."
And so to the big day. With a special leaf-green suit and a cream blouse, Ms McCrae arrived in London to take her place alongside the great and good of Britain. She had not even told her colleagues that she had been invited to the lunch, just that she was taking a couple of days off.
"I told the boss that I was coming, but nobody else," she said.
"I was quite nervous last night and then again this morning wondering who I would be sitting next to and who else would be there."
At the door of Mansion House, designed by George Dance the Elder and first used by Sir Crispin Gascoigne who took up residence in 1752, Ms McCrae and other guests were met by Lord Levene and shown to their seats.
Ms McRae sat next to David Mackie QC, the first solicitor in Britain to take silk and Parviz Habibi, the doctor who set up the first emergency retrieval teams to save children struck by meningitis. Though both are well known in their own fields, they could not be described as celebrities: Ms McCrae recognised neither of them.
"I didn't really speak to any of the celebrities. It was strange seeing them in the flesh because you normally only see them on television," said Ms McCrae. "Then again they are all just the same as you and me."
The meal was an elaborate affair, served upon Wedgwood china with gold cutlery. Given the explosive food controversy with the French, one can only presume the decision to serve a starter of foie gras with truffle sauce with a Sancerre 97, was one taken quite some time ago.
Guests were on much safer territory with the main course - buccleuch tornedos made from British beef - followed by lemon and chocolate tart. The red wine was a Spanish Rioja.
"The food was very nice. I ate everything," confessed Ms McCrae.
After a series of toasts and a couple of speeches, the guests steadily made their way out of the Egyptian Hall mingling together as they waited for their coats. Lady Thatcher raced by in a flash of blue, while Patrick Moore lumbered slowly down the carpeted stairs, careful not to displace his monocle.
"I think there was a good mix of people," said Ms McCrae.
"There were people from all different walk of life and it was good that they invited some ordinary people as well. I think the balance of guests was probably about right. I had a lovely time."Reuse content