She was born Lesley Hornby on 19 September 1949, and was brought up in the northwest London suburb of Neasden. She was the third daughter of Nellie Lydia (née Reeman), a factory worker for a printing firm, and William Norman Hornby, a master carpenter and joiner from Lancashire.[8] Her maternal grandfather was Jewish.[9] Their first daughter, Shirley, had been born fifteen years earlier; their second, Vivien, had been born seven years earlier.[6]
Twiggy's mother taught her to sew from an early age. She used this skill to make her own clothing.[10] She attended the Brondesbury and Kilburn High School in Salusbury Road, London.
Twiggy's great great grandmother, Grace Meadows, then living under her maiden name Grace Gillies, died in a stampede of Jewish shoppers at a bargain sale at Messrs McIllroys store in Mare Street In Hackney in 1897. This event made the news at the time.[11]