Her family migrated at the turn of the century from Ireland to Canada, soon moving to Buffalo, New York.

[1] An uncle named Charlie Zimmerman, a music director, encouraged her artistic talent and took to theater choirs.

Robert Courtneidge a producer who travelled to the United States, met O'Neil.

[5][6] In the autumn of 1928, at the National Radio Exhibition she noticed John Logie Baird's television in the Olympia, London.

Roles in The Razor's Edge, Let's Dance and (body doubling for Ingrid Bergman) Joan of Arc followed.

As a painter, she presented three oil paintings to the public Wertheim Gallery and Burlington Gardens.

[1] From the mid-1940s, she was increasingly plagued by arthritic pain, which soon led to her being unable to leave home and relying on a wheelchair.

[8] She died impoverished on 7 January 1960 at Middlesex Hospital in London from heart failure.