This Was Sylvia

This was Sylvia was a 1957 Australian radio serial by Coral Lansbury.
Lansbury said there were two main types of serials – one about a noble woman "with whom the listener can identify herself", the other "about a monster who will have the effect of catharsis on the listener, and inspire her to feelings of rage and hate and contempt." This was Sylvia was the latter, about a woman who robs her mother and marries her best friend's fiancé.

Premise

From the National Film and Sound Archive: "The infinite beauty and insatiable ambition of Sylvia Giles meant the ruin of three men. The theme of this dramatic story is summed up in Sylvia's words: 'Women fall into two classes – those whom men make use of and those who make use of men. I've always known to which class I belonged'."