For more than 42 years, Ms Proops dealt with tens of thousands of letters each year from readers whose problems changed to reflect the times. In 1954, her column in Woman's Mirror contained veiled references to sex; by 1996, the problems of heterosexual and gay relationships, drugs and the terrors of Aids were all handled openly and with her trademark sensitivity.
It was not until four years ago, however, that one of the reasons behind her ability to empathise so well became apparent when, in her autobiography, she confessed that her own marriage of 53 years to her husband, Sidney, had been a sham. For 30 of those years, she told her sympathetic readers, she had been involved in an affair with a newspaper lawyer, Phillip Levy. From some, such a revelation would have been viewed as hypocrisy; from Marje it felt like collective catharsis.
Last night, her peers in journalism were mourning her loss. Her fellow agony aunt Claire Rayner said: "She was a remarkable woman. I shall miss her, she was terrific.
"She had a long life and she worked right to the end. Her column appeared last week and that would have been very important to her. She cared hugely about her readers."
David Montgomery, chief executive of the Mirror Group, said: "I first met Marje when I was a young sub-editor and she left me in no doubt who was boss. She demanded the highest standards, and that determination never left her.
"Until her last working day last week, Marje's involvement with the Daily Mirror remained 100 per cent, ranging over the whole paper as well as her columns and comment."
Anna Raeburn, another agony aunt, said she had been told that Ms Proops had deliberately concealed her age from employers "so that they couldn't fire her or retire her. As it's so hard for women to work at that echelon, I would like to believe it, and good luck to her. She was terrific, and she did some very good writing."
There was praise, too, from the world of politics. The Labour leader, Tony Blair, said: "She was a legend in journalism and will be sadly missed, not just by the Daily Mirror and its readers, but by the country, who came to appreciate her warmth and generosity."
Lady Olga Maitland, Tory MP and former newspaper columnist, said: "She was a Fleet Street institution, beloved by everybody. She was a woman of the old school with tremendously high standards. She would never stoop to some of the journalistic behaviour of today.
"She had great integrity, tremendous insight and warmth and she will always be remembered for her high standards and sheer professionalism."
Following a series of anti- Semitic experiences in central London after the First World War, Ms Proops changed her name from Rebecca Rayle. She began her career as fashion editor at the Daily Herald in 1945 and by 1954 was agony aunt on Woman's Mirror.
In 1971, her column, "Dear Marje", was established. Its popularity grew rapidly, resulting in the paper having to employ a staff of eight to deal with up to 50,000 letters a year - each one of which received a reply.
Her left-leaning politics and sympathetic attitudes took her to the forefront of liberal campaigning. In 1994, she led a delegation of agony aunts to Downing Street to push for the lowering of the age of consent for homosexuals to 16.
"As the law stands, I cannot give any homosexuals under the age of 21 [as it was then; it subsequently came down to 18] any advice because their activity is illegal," she said at the time. "I see nothing wrong in 16- year-old youths expressing their sexuality with people they love. At 16, girls and boys know their sexuality."
In other areas, however, she found herself less tolerant. In her final years, she expressed concern over the amount of sex and violence in films and on television.
Revealing her own problems in , Marje, The Guilt and the Gingerbread, she said she married Sidney because he was the only boyfriend who had not dropped her for her prettier sister. They had one son, Robert, in 1935, but their marriage was a loveless relationship.
"I couldn't bear him to kiss me," she wrote. "I lay in bed beside him quivering with horror. In the end, I told him: 'I can't go on with this marriage. I've got to leave you.'" But she never did. Instead they stayed together platonically. Explaining why she decided to expose the deception, she wrote: "If a person carries a secret which creates an enormous load of guilt, the only relief is by confessing your sins."
She once said that if she had to die, then her the Mirror would be her ideal place. "Then, in the morning, the cleaners will find me and sweep me up," she said.Reuse content