Born Charles Emmett McNerney in Scranton, Pennsylvania, to an Irish family, at a young age Mack could speak three or four languages.

One of Mack's early jobs was as a peanut vendor at the Ringling Brothers Circus.

One day, Griffith invited Mack to rehearse a scene from Dream Street with him.

I thought it all terrible, but he seemed to think it good, and so I kept on acting instead of going back to the property room.While filming America in 1924, a soldier's arm was blown off.

A 1929 issue of Picture-Play revealed that it was anticipated that she would perhaps become a leading actress, but it doesn't seem her career ever went past bit parts.