In July 1988 she won the English Schools 1500 m title in a British record (under 15). Running for Devon, she finished eight places and 13 seconds ahead of Paula Radcliffe, running for Bedfordshire. Pavey then won the AAAs national U15 800 m and 1500 m titles in 1988 and the AAAs national U17 800 & 1500 m titles in 1990. She made her Great Britain & NI debut in Athens in 1989 as a fifteen-year-old competing as an under twenty.