It all started in the week of her 19th birthday, before she had even worn her Northern Ireland kit for the first time. 

"I met some of the Australians who came to compete in Belfast before the 1958 Games in Cardiff," said Peters a few years ago. "We're still good friends 60 years later."

One of those friends, Marlene Mathews, won the 100 and 220 yards double in Cardiff. Peters finished unplaced in the shot and high jump, and sixth in the sprint relay on her international debut.

"I was deliriously happy just to be there," said Peters, who regarded the trip as "a super, exciting holiday" and spent one of her evenings riding the dodgems and eating candyfloss with a group of boxers at nearby Barry Island.

"Every moment was a joy." 

By the time she made her fifth and final appearance at the Commonwealth Games 16 years later, in Christchurch, Peters was an Olympic champion and one of the all-time greats of British athletics, revered on both sides of the sectarian divide in Northern Ireland. 

She desperately wanted to win, having already announced that the 1974 Games would be her farewell. She was determined to enjoy herself, too.

Peters flew out early with Mike Bull, the decathlete, via pre-Games training in California. "I have very warm memories of Christchurch," she said.

"I'll always remember the end-of-Games athletes' parade. I persuaded the biggest man in the Village, a Canadian shot-putter, to carry me round on his shoulders. And he curtsied when he passed the royal box."

That was quite a sight as the carrier, Bruce Pirnie, stood at 6ft 7in tall and weighed 22 stone before he added Peters to the equation.

It was a case of "mission accomplished" for Peters and Bull. They had both been coached by Buster McShane, owner of the gym where Mary worked in Belfast, who had died in a car crash 10 months earlier. They both wanted to win for him.

Bull won the decathlon and Peters triumphed in dramatic style, just as she had done in Edinburgh four years earlier. In 1970 it was victory in the final event, the 200 metres, that held off the challenge of Ann Wilson of England. 

It was even closer in Christchurch, with the Olympic champion under threat from Modupe Oshikoya, a Nigerian who, at 20, was 14 years younger than Peters. This time Peters had to finish within one second of Oshikoya in the 200m, and she did it with 15 hundredths to spare.

The low point for Peters had also come at the Commonwealth Games, in Kingston in 1966. There was no pentathlon until 1970 and Peters was beaten in the shot, her only event, and one in which she won another gold in Edinburgh. She felt that had been a wasted year and said: "I was furious with myself. I should have won it."

There were many triumphs to come though, not just on the athletics track. Peters' work in athletics and in the community during three decades of The Troubles in Northern Ireland led to her being awarded an MBE and a CBE before she was made a Dame of the British Empire.

A local athletics track is named after her, she is Lord Lieutenant of Belfast, and she played a leading role in the London 2012 Olympic Games Opening Ceremony.