She was invited to join the Abbey Theatre in 1924 and acted alongside some of the great names of the day, such as Cyril Cusack, Maire O'Neill and F. J. McCormick in numerous plays.
[1] She played the part of Rosie Redmond in The Plough and the Stars on 8 February 1926, when the players were attacked during a riot in the theatre.
It was a difficult time for the Abbey, and Mooney had to contend with a demanding manager, Ernest Blythe, with whom she did not see eye-to-eye.
Among them were Ronnie Masterson, Joan O'Hara, Ray McAnally, Philip O'Flynn, Angela Newman, Bill Foley and Doreen Madden.
Between 1948 and 1963, seventy-five new plays were produced at the two Abbey locations; most of these were directed by Mooney, and most received excellent reviews from the Dublin critics.