Born in Hong Kong in 1955, Ferry had a peripatetic childhood as one of five children of an army officer. She went to Ellerslie School in Great Malvern from 1966–73, then to Lady Margaret Hall, Oxford: she graduated in Experimental Psychology in 1976. She worked briefly for a science publisher before joining New Scientist magazine as a section editor. Soon afterwards she began to present science programmes on BBC Radio 4. She married David Long in 1981. They settled in Oxford, and sons Ed and Will were born in 1982 and 1985. Since then she has worked mostly as a freelance writer, editor and broadcaster.