Her birth provoked no angry interrogation or recriminations from her father — merely delight and unquestioning acceptance.
Yet Georgina was not the baby either of her parents had been expecting. They were both white while she, with her tightly-curled, charcoal-coloured hair and huge brown eyes, was unmistakably black.
If Jim Lawton, a kind, mild-mannered giant of a man, had any misgivings when his first child arrived at Queen Charlotte's Hospital in Hammersmith 28 years ago, he kept them to himself. Only his evident pleasure at first-time parenthood is chronicled.
'He was elated — a daughter! He cooed and cuddled and accepted me without any question,' recounts Georgina in her powerful new memoir Raceless, drawing on the knowledge that she was unconditionally loved by both parents.
But while Jim embraced the new arrival, his wife Colette's mind was racing. Her relief at giving birth to a healthy girl was swiftly usurped by shame and trepidation.
She knew straight away. Her baby was the result of a one-night stand she'd had with a black barman at a pub in Shepherd's Bush exactly nine months earlier.
She told no one about this secret — her guilt exacerbated by her strict Irish Catholic upbringing — until after Jim's premature death, aged 55, from cancer in 2015. And remarkably Jim never questioned why his daughter looked so different from both her parents.
Pictured: Georgina Lawton as a young girl with her father, Jim Lawton. If the mild-mannered giant of a man, had any misgivings when his first child arrived at Queen Charlotte’s Hospital in Hammersmith 28 years ago, he kept them to himself. Only his evident pleasure at first-time parenthood is chronicled
Meanwhile, a midwife threw the couple a lifeline that would anchor the story of brown-skinned Georgina into their solidly suburban Caucasian lives.
The reason this beautiful baby was so different in complexion from her parents was doubtless down to a 'throwback gene' from a distant lineage, she said.
After all, wasn't Colette Irish? And hadn't there been lots of racial mixing on the West Coast, where she was raised, close to a town called Spanish Point in County Clare? Could it be that crew from the ships dispersed by the Armada — Spanish and Portuguese sailors had arrived there in the 16th century — had widened the gene pool?
Jim and Colette clung to this convenient, but preposterous, fiction; indeed it became part of their family folklore, the reason they gave to Georgina and others, to explain her differentness.
The falsehood persisted unchallenged. Georgina — contrary to the evidence of everyone's eyes — was actually white, they insisted.
'It was a story my mother would repeat again and again, and one I would learn to recite hundreds of times,' writes Georgina, as she recounts the far-reaching effects this denial of her race had on her.
Colette was a loving, devoted mum; insistent that her children were always impeccably presented for school. The marriage, too, was happy and full of laughter.
But beneath the surface lurked her persistent disorientation; a restless anxiety to understand why she looked so unlike her family.
The first intimation that she was different came from a five-year-old girl at school — button-nosed and, like all the other girls in the class, white — who suggested Georgina scratch her skin to make it white.
Georgia experimented. It worked! But she concluded she didn't want to abrade her entire body just so she could conform.
Next, at her high-achieving, predominantly white Catholic secondary school in Carshalton — a suburb of crumbling antique shops, artisan bakers and historic buildings, presided over by a large duck pond — she excelled. 'I worked hard to over-compensate for standing out in every social space I occupied,' she recalls.
But she also encountered cruelty. A teacher questioned her publicly on why her ethnicity was marked as 'White British' on the school's records. Was it a mistake, she was asked.
Georgina's resolve faltered: 'Both my parents are white and that's all I know really...' she offered. The teacher was not appeased. 'But that doesn't make you white, does it?' she persisted. 'Do you think there was some mistake at the hospital when you were born?
'Were you adopted without being told? Or perhaps there's been an affair? I'm just wondering how this could have happened.'
Georgina (pictured) was not the baby either of her parents had been expecting. They were both white while she, with her tightly-curled, charcoal-coloured hair and huge brown eyes, was unmistakably black
The questions, insistent, intrusive, utterly mortifying, stayed with her. That evening she told her parents about them. 'Nosy old cow!' was her mother's retort. Her father's forehead furrowed. The well-worn story about being a genetic throwback was reiterated; the blame attributed to the teacher for her intrusiveness.
And the sense of her separateness only deepened. With her friend from school she got a weekend job at a National Trust café — the very apex of Britishness — and noticed, for the first time, that black male customers flirted with her.
Was she 'habesha', one asked. At home she Googled the term and found it meant someone originating from Ethiopia. Was the teacher right? Had there been a mix-up of epic proportions at the hospital when she was born?
But her parents persisted with the story of the genetic miracle and, cossetted by their love, she did not try to unpack the lie.
And while all her extended family — grandparents on both sides; aunts, uncles and cousins — never questioned her skin colour (she later learned that they followed the cue of her parents' silence on the matter), when she encountered strangers there was no such tact.
There was a pause. 'Well your father didn't say anything when you were born. After that it just sort of continued. We carried on with life. We had your brother. And we were happy, weren't we?'
For Georgina to understand her mother's reticence she had to appreciate the shame that surrounded illegitimacy, infidelity and dual-heritage children in Catholic Ireland.
In 1961, when Colette was born, the stigma a*sociated with s*x outside marriage still prevailed, exacerbated by the Catholic Church's tendency to sweep indiscretions under the rug.
When illegitimate children were also mixed-race, another layer of racism compounded the distress of these 'fallen' mothers.
And by making his choice to stay, Jim had absolved Colette from the public shame that would have surrounded her one-night stand. Georgina concluded he had done her an incredible kindness by taking her on.
'I could see why things had happened the way they had; the thoughts, dreams and plans they had realised for our family by simply staying together without a word.' She concludes: 'I was their Gina, their doll-face and nothing would ever change that.'
There were other questions, however, she needed to answer. She took an ethnicity test which revealed that 43 per cent of her black ancestry originated in Nigeria. She made further investigations, questioning her father's closest friend about whether he knew the truth about her heritage. He did not.
She visited her father's parents and his sister Celia in Shropshire. 'Nothing was ever said. We all accepted you as Jim's daughter. We still do,' said Celia simply.
As for Georgina's kind, eternally busy granny, she declared she'd always believed Georgina was her son's. Conversely her grandpa had 'always known' she couldn't be, but embraced her as their own all the same.
It was Jim's dying wish that the family he strove so hard to keep together, 'just stay together as best as you can'.
For Georgina, who now works as an author and journalist, he continues to be a light in her darkest hours.
'If I can live my life with just one smattering of Dad's values, if I can take one tiny cell of his selflessness and carry it with me for ever, then I know I will be better for it,' she concludes.
'If we do it right, the way we live our lives, the reach of our actions and the things we do for others will leave a mark on the world long after we are gone.
'A love like my dad's comes round once, maybe twice, in a lifetime, but its imprint remains etched on to the hearts of everyone he touched, immovable and everlasting, in spite of his physical absence.'
Georgina has not found her biological father — the need does not seem pressing. Actually, a small part of her wants him to stay in the shadows, so it never dims the light that still shines from her real dad, Jim.