Born, before her parents were married, she grew up in the family terraced house in Mansel Street which housed, in addition to her mother and father, two uncles and her grandmother and grandfather. Hers was a happy childhood, with love and affection, surrounded as she was, by this extended Welsh family that helped to forge the future Mavis and explains why she once said : “I’ll tell you what I did have, a great instinct about people”.
She revealed this closeness of familial relationships when, reflecting on her early years and said : "My mother had twins six years after me and I was the apple of her eye till then and she never told me that she was having babies. I didn't know. And they came home, two babies and me spoilt, and suddenly I had to leave mother and father's bedroom, we were very overcrowded, and sleep in (her grandmother) Martha Jane's bed and I remember the first night I was in that bed, big bed, feather bed and Martha Jane said : "Move over. You've warmed that up nicely for me. You get into the cold bit" (link)
Broadcaster and journalist Carolyn Hitt, met Mavis in 2016 when filming the BBC documentary, 'Being Mavis Nicholson : TV's Greatest Interviewer' and said "Bette Davis, Kirk Douglas, Lauren Bacall, it didn't matter how major the celebrity and how many times they had played the interview game before, Mavis got something from them that no-else could. The alchemy of her interviews was part journalism, part psychotherapy plus the relentless curiosity which is perhaps peculiar to a certain kind of Welsh working-class upbringing. Anyone who, like Mavis, grew up in a household where strong women constantly chatted, gossiped and debated will recognise it".
Mavis later reflected : "My mother said to me around the time when I was on telly - she said : "Do you know what I said to you, but you were too young to hear me say it ? : "You've got something that makes people want to talk to you", because when you were outside in your pushchair and I was rushing into the butcher's, I'd come out and there was at least one person talking to you". She said I had the kind of face that people wanted to talk to and that she was never surprised that I was a good interviewer and became successful. When I was about ten she asked me what I wanted to be ? I said : "Maybe a teacher". My mother said : "You can be anything - even a film star". There's no doubt about it, she really gave me my confidence".
In 1940, at the start of the Second World War Mavis won a scholarship and gained a place at the Neath Grammar School for Girls and seen here, standing in third row, third from the left. The 1946 Jubilee edition of the School Magazine confidently asserted that : 'The school this year is represented by students at many universities' and went on to point out that although generally girls’ careers were teaching, clerical or nursing, the school had one engineer who had passed her Mechanical Sciences Tripos examination in 1942 and further, that no woman’s name had appeared on the Cambridge Engineering lists for 16 years.
Outside school her childhood mentor was Eileen Sims, a classics graduate with a double first, who was a deacon at the local Jerusalem English Baptist Chapel, where at 14, Mavis was baptised with seven others in a tank of cold water. It was known locally during the war as “the conchies’ chapel” and might well have been attended by some of the 400 Baptist, conscientious objectors who refused to fight in the Second World War at this time. Some years later Mavis was true to her Baptist roots when, in 1981, she was, as a vocal opponent of nuclear proliferation and demonstrated with the other women at Greenham Common and in 2002, marched in London in protest against the war with Iraq.
Mavis took her religion very seriously in her teenage years and said : 'I did have a real zeal for religion - I was up in pulpits preaching the brotherhood of man and praying with heart and soul for it - without losing my equally strong devotion to clothes and make-up, the cinema and boys'. She a special relationship with Miss Sims or 'Simsie', who gave her out of school lessons in Latin to ensure that she could enter the sixth form at school. In a remarkable early example of her curiosity and need to draw people out, she had once, on one of their slow walks to the chapel, asked Simsie if she'd ever been in love ? To which she replied : "Once. Don't ask me any more. It's a hopeless case. I have never told anyone and never will, because it is out of the question". Mavis persisted and said : "Does he know ?" to which Simsie replied : "Heavens girl, absolutely not and never, ever will. That's why, Miss M, you must not ask me anything more and please don't try to guess".
On leaving school in 1948, having gained a place at University College of Swansea to study Economic History, she later said : 'When I left home for college, though I didn't know it at the time, that day I left hone for good'. Before leaving she was full of foreboding and : 'The sickening terror I felt at the prospect of sharing a room with a girl called Mary Davies, a 'doctor's' daughter' who would find out that, at home, she didn't have a bathroom. Before she left she gave Sarah Jane a hug and said : "Grandma, you were like a mother to me when I was little. I'll never foreget that". She also wrote to Simsie, 'Dear Miss S, I know that God has been good, that He is the one way ... but Simsie, there's a heap of weakness in my heart and I need more heavenly guidance. I need a human prod which is what you are'.In 1949, now a second year student at the age of nineteen, at midnight on that New Year’s Eve in 1949 she met and started her affair with fellow student and future husband, Geoffrey Nicholson and recalled : "As the clock struck 12, Geoff walked towards me - poetic-looking, very thin, long hair, which no one had then, and in a red shirt which no one wore - said, "Happy New Year", and kissed me".
Geoff, who was a year older than her, was a first year student who had elected to do his two years national service as a lance-bombadier in the Royal Artillery, before studying English Literature at the university. Like her, Geoff, the son of a Saxone shoe shop salesman, came from a working class background and it was at the University that they both made the acquaintance of the young, the then, left-leaning, twenty-six year old English Literature lecturer, Kingsley Amis, he himself the son of a clerk for the mustard manufacturer Colman's in the City of London. Mavis, in fact became one of Kingsley's many mistresses shortly after the marriage and agonised over the affair. Kingley's wife Hilly, who counted Mavis a friend, had known about it, but did not demur, partly because, as she later said : “She was never a threat, we were all in love with Mavis”.
In London and in their twenties in the 1950s, the Nicholsons became the centre of a lively social circle, including included the actor Maureen Lipman and journalist Valerie Grove and the Welsh journalist and broadcaster John Morgan who worked for BBC TV. The circle included included Kingsley, who after the publication of 'Lucky Jim' in 1954 was now, 'novelist', Kingsley Amis. According to Peter Corrigan, the Nicholsons : 'Became a much-loved double-act. Amis did not always approve of their views and claimed to have invented the word 'lefties' during one little set-to with them. While it was true that the Nicholsons didn't have dinner parties as such – they invited people for an argument and threw some food in – they were by no means belligerent but had in abundance the Welsh love of debate'.
Mavis found work a journalist on women’s magazines, including the radically chic 'Nova' in the 1960s and then left her professional life to devote herself as the mother of her three sons and financially supported by Geoffrey who himself was a modest, unassuming man, to whom family mattered more than career but nevertheless became highly successful as one of a small team on the 'Observer' newspaper. It was there that he helped to transform the character of sports journalism in the late 1950s by introducing a quality of writing that matched, and was sometimes superior to, that on the arts and foreign pages.
In 2018 when Mavis was given the BAFTA Cymru Special Award for her 'Outstanding Contribution to Television', in St David's Hall in Cardiff she said : "I was absolutely flabbergasted. Then I thought 'be confident girl' and say "how wonderful it's about time"".