From Wikipedia, the free encyclopedia. Kate Isitt is an English actress who is best known for her role as beauty therapist Sally Harper in the BBC television situation comedy Coupling. From 1995-1998, she played Alison, a secretary in a solicitors' office, in Is It Legal?. Isitt had a minor part in the film of The Saint (1997). In 1998 she played alongside Alan Davies in "Black Canary", an episode of the BBC TV mystery series Jonathan Creek, and as Davies' wife in a pilot episode of the BBC comedy, A Many Splintered Thing (of which a series …