Born Lesley Hornby in Neasden, a suburb of London, she became famous at the age of sixteen, under the influence of her boyfriend and manager, Justin de Villeneuve. Soon she was regarded as "the face" of swinging 1960s London, and gained her nickname from her stick-thin pubescent figure. As she matured, she ditched Villeneuve and broadened her horizons, appearing as an actress and singer, notably in Ken Russell's 1971 film version of The Boyfriend. Since then she has played a variety of roles on stage and screen, including Eliza Doolittle in Pygmalion, opposite Robert Powell, in a 1981 television production.
Her first marriage, to American actor, Michael Witney, ended with his sudden death. In 1988, she married the actor Leigh Lawson.