As she enjoyed domesticity, George got his first guitar and formed a group called The Rebels with his brother, Peter. He became friends with Paul McCartney, who was a year above him at the Liverpool Institute school, and was asked to join The Quarrymen, the precursor to The Beatles.
In October 1962, Love Me Do was released and Britain became gripped by Beatlemania.
The band was unknown in America. But, thanks to Louise, their big break wasn't far away. She wrote to American small-town DJs asking them to play her brother's records.
She got From Me To You played by a local station in Illinois in June 1963 - the first U.S. airplay The Beatles received.
'I did all I could to help my kid brother,' she says. In 1963, George spent two weeks at Louise's home.
He was able to walk the streets unrecognised, he went camping and played with a local band in front of a small crowd of 150.
Five months later he returned to the U.S. with The Beatles to appear on The Ed Sullivan show.
It was, of course, an entirely different event, with hordes of screaming fans greeting the band's plane.
Louise travelled to New York to see The Beatles, and partied with Cynthia Lennon and Harrison's then girlfriend, Patti Boyd.
George was suffering from a sore throat and Louise was asked by doctors to administer his medicine - on the grounds that the nurses would probably be overwhelmed by his fame.
Louise later recalled chatting to George backstage in Cincinnati in 1965, and asking him: 'Why are you bothering to tune your guitar? No one's going to hear you.'
He replied: 'I always have this scary feeling that all of a sudden they might stop screaming and I'll be out of tune.'
It was the best of times for Louise - she got her own local radio show on the back of her fame by association and was once considered for a presenting job on U.S. television.
But trouble was looming. Her husband, Donald, disapproved of his wife's celebrity lifestyle and filed for divorce in 1970.
Louise moved to New York and spent a lot of time with George 'just hanging out'.
They were both single - George was between marriages (Patti had left him for Eric Clapton and he was yet to meet second wife Olivia).
The Beatles broke up that same year and George found comfort in spending time with his 'big sis'.
Louise never tired of telling the story of The Beatles and her link to them. In the early Nineties, her house in Illinois was turned into the Hard Day's Nite B&B - a guest house with a Beatles museum.