Harrison made her acting debut in 1976, in the BBC police drama, "Softly Softly", which was a spin-off from the hugely popular "Z-Cars". In 1980 she made her film debut, securing a minor role in the 1980 adaptation of "The Elephant Man". She went on to appear in many successful television programmes including "The Gentle Touch" (1982); "Q.E.D." (1982); "The Cleopatras" (1983); "Minder" (1984); "Casualty" (1987, 1996 & 2008); Dorothy in "London's Burning" from 1988–1989; "Kavanagh QC" (1995) and ITV's "A Touch of Frost" (1997).