Daughter of bit part actor James Donlan.
She began her film career in the late 1930s playing tiny parts (Pennies from Heaven (1936), Rosalie (1937), Love Finds Andy Hardy (1938)) under her real name, and as either Yolande Mallott or Yolande Mollot.
Scored a personal success first in Boston, then on the London stage as Billie Dawn in "Born Yesterday" and decided to settle in England, where she continued filming.
She was seen playing Billie Dawn in the United States by Laurence Olivier, who brought her to Great Britain to play the part.
Son with husband Philip Truex: Christopher, born January 14, 1946, at Manhattan's French Hospital (NYC).