Potter is educated at St. Mary’s school in Fairview. She has a long career in Irish theatre, mainly as Ireland’s première comedienne, but also as a straight actress. She first appears professionally with Jimmy O’Dea in pantomime and appears frequently on television and in cabaret. She is a regular performer at the Gaiety Theatre in Dublin and for many years stars in Christmas pantomime. She becomes the first star to have a bronze cast of her handprints outside the theatre. She marries Jack O’Leary in 1959, an Irish army officer whom she had first met in 1943, and he writes most of her comedic material.
Among Potter’s many dramatic roles in the theatre is that of Maisie Madigan in Juno and the Paycock. While still a teenager, she tours abroad before World War II as a singer and dancer with Jack Hylton and his orchestra. On a tour of Germany, they once perform in front of Adolf Hitler and other Nazis. She plays the role of Dante Riordan in Joseph Strick‘s film, A Portrait of the Artist as a Young Man (1977). In September 1938, she appears on the BBC Television Service with Jack Hylton and his band. Film of her performance is held by the Alexandra Palace Television Society. In 2001, the Archivist of the Alexandra Palace Television Society gives Potter a copy of her 1938 television appearance.
Potter is conferred with the Freedom of the City of Dublin in 1984, and is later awarded an honorary degree from Trinity College, Dublin. She dies in her sleep at her home in Clontarf on April 7, 2004, at the age of 79. She is survived by her husband Jack O’Leary, and her sons John and Hugh.