[2] Her stage performances were broadcast live nationwide; on radio she played siren art teacher Jane Petrie in The Archers.
Michael Barry, Head of Drama at BBC Television, adapted the performance for broadcast on 21 March 1948 as Scenes from Twelfth Night and Macbeth.
In 1954 O'Leary participated in a long repertoire of plays at the Grand Theatre, Wolverhampton: Affairs of State; The Letter; Birthday Honours; Friendly Relations; The Orchard Walls; The Gay Dog; Someone Waiting; Jane Steps Out; The Constant Wife; The Happy Marriage; The Trial of Mary Dugan; Are You a Mason?
[18] O'Leary became best known on television for the role of Mary the anxious wife of manager, Gerry Barford (David Lodge), in the 1960s BBC soap opera, United!.
Her distractions while running the summer school at Arkwright Hall gets Tony Archer (Colin Skipp) the sack from Ralph Bellamy's dairy enterprise.