"Penny" Moyes was born in Dublin, Ireland, on 19 January 1923, the daughter of Marion ("Molly") Strachan and Ernest Pakenham-Walsh, who had been in the Indian civil service and was a High Court judge in Madras.
In 1960 she co-wrote the screenplay for the film School for Scoundrels starring Ian Carmichael, Terry-Thomas, and Alastair Sim.
During her next job as an Assistant Editor for London Vogue, Moyes also translated Jean Anouilh's 1940 play Léocadia as Time Remembered.
The 1957 Broadway production – starring Richard Burton, Helen Hayes, and Susan Strasberg — received several Tony Awards.
The success of Time Remembered enabled Moyes to leave Vogue and start writing mysteries.