She learnt typing and shorthand before following her elder brother Victor into the acting profession, training at Herbert Beerbohm Tree's Academy of Dramatic Art.
Two years earlier she had married Delia's brother, Jack de Leon, a solicitor with an interest in the arts.
[2] On Boxing Day that year, the first production was Gertrude Jennings' successful comedy The Young Person in Pink; in which De Leon made her professional debut as an actor.
[1] Plays continued at the Q Theatre until 1929 when disagreements led to the De Leons stepping back.
De Leon and her daughter Jean ran a dance studio at the Richmond Adult College for 30 years.