Real age of Ann-Margret in Once a Thief
In the movie Once a Thief, Ann-Margret was:
23 years old
That was the real age of the celebrity according to our calculation.
The calculation of the shown age took into account the first day of the year in which the movie Once a Thief was released:
January 1, 1965
And the day in which Ann-Margret was born:April 28, 1941
Since movies usually don't take more than one year to be released since the beginning of the filming process, Ann-Margret may have been one year younger or one year older than the shown age while some scenes of the movie were being filmed.