On an annual CND march from Aldermaston she met Barry Miles, known invariably as Miles. He, too, was a fan of the beat poets and ran a magazine to which such figures as Lawrence Ferlinghetti contributed. They married, eloping to Scotland, since her parents refused to accept the match – and in London found themselves at the heart of what was known as the "underground". Together they set up the Albert Hall poetry reading, with Allen Ginsberg performing, and 6,000 nascent hippies in the audience; the underground's first newspaper, IT (the International Times); and Indica, the avant-garde art gallery and bookshop for which Paul McCartney designed the wrapping paper and where John Lennon first met Yoko Ono. Sue also ran the Arts Lab cafe, her first essay at catering.
In 1970 the couple moved to the US, to Ginsberg's farm in upstate New York. There the marriage collapsed and after a spell at the East Side bookstore in New York, Sue returned to London.