Social work chief and Special Branch agent; Born August 27, 1912; Died May 9, 2007. No-one would ever have known that Margery Urquhart had been a spy. Certainly not her colleagues at Grampian Regional Council, where, in her role as director of social work, her trademark was an unassuming demeanour. She personified the cliché that no-one would ever have picked her out of a crowd.

Her record is that she was probably the first female agent recruited by Special Branch, she was the first female to reach senior rank in a Home Counties police force and she played an unknown role in counter-espionage in the UK before and during the Second World War.

Alongside this, it's almost an incidental that she was one of the first women anywhere to graduate with a BSc in agriculture, and that she helped pioneer children's welfare as part of local authority responsibility.

Margery Urquhart was born in Patagonia, Argentina, where her father ran a beef business. Until she was 11, her mother educated her on the ranch, before the family returned home to Milton of Culloden, Inverness. She graduated from Aberdeen University in 1935, heading to Hampshire to begin farming.

Then, in the first of a series of career switches which frequently left colleagues both baffled and in admiration of her polymathic abilities, she dropped plans for a career in agriculture to join the Metropolitan Police.

Even within the police, she switched. In a pioneering role, she developed her work to become involved in crimes by and against children, and rape. It was her police background allied to her ability to change guises so convincingly that brought her to the attention of Special Branch. She had been "noted" by a local head of Special Branch, and he recruited her as his first female agent. After training, she was used in covert operations against prewar IRA agents. This was serious business, for in Coventry in 1937 the IRA had exploded the first bicycle bomb.

Though her male colleagues were frequently armed, Margery was not. But on one occasion, knowing that violence might ensue, she armed herself with two empty half-pint milk bottles in her handbag. She also chased an armed IRA man along The Strand in London, and when he jumped on a bus to elude her, she followed on the next bus.

To the end of her life - and she died in her 95th year - she refused to discuss her Special Branch role or the fact that she had also been involved in counter-espionage work, gently pushing aside all references to it.

Councillor John Porter, Tory group leader on Aberdeen City Council and a one-time colleague, said: "I don't think anyone will ever know exactly what she did. To look at her, you would think she had just put down her knitting."

When Surrey Police Force recruited women for the first time in 1942 - initially employed only on a temporary basis and known as the Women's Auxiliary Police Corps - Miss Urquhart took command as first woman inspector in the Home Counties in 1944 when permanent establishment of the corps was authorised. The recruiting notice for women officers stated that they had to be "of average intelligence and single, although they could be widows".

Two years later, in 1946, she promptly changed direction yet again to train as a probation officer in London, saying that children were her first love.

In 1949, she returned to Aberdeen, becoming first children's officer for the city. This, too, was something of a pioneering role, with Margery making clear the value she put on steering broken families and troubled children towards better paths. Of those early days, Margery herself said: "There was a sense of mission. I left the police but I could not leave child care."

That sense of mission manifested itself with Margery herself appearing at children's homes at weekends to help care for youngsters. "Her" children had reason to be grateful to her, and many kept in touch for years afterwards.

She became the first head of social work for the old counties of Aberdeen and Kincardine in 1969, and six years later became deputy director of social work for the newly formed Grampian Region, later rising to director.

Her reputation for keeping her own counsel and maintaining an unassuming manner greatly impressed all who came into contact with her. A warm, caring person who remained calm no matter the stresses, she always gave a good account of herself in local authority work, impressing elected members with her ability to present arguments and marshal facts.

She retired in 1977 and soon afterwards stood for her old council, gaining the Aberdeen Tory seat of Hazlehead. Back in Grampian Regional Council in her new guise, she worked quietly and rarely spoke - though when she did, her audience tended to pay attention.

In 1977, she was made OBE, and made her investiture at Buckingham Palace memorable for two reasons. Waiting outside to congratulate her was one of "her" boys, a one-time tearaway from a broken home in Aberdeen but now a successful businessman. Then on the Tube, in what was for her an unusual moment of forgetfulness, she left behind her hat and the shiny new insignia of her OBE. Happily, both were returned to her.

She never married, and died in a nursing home in Aberdeen.