The 40-year-old actress is said to have flaunted the slim figure of her youth when she stripped down to her knickers in the movie- "In Their Skin", reported Sun online.
The 'Anger Management' actress, who was pregnant while making the film, had given birth to her son Arthur Saint Bleick, a few months after shooting the movie.
Blair and co-star Joshua Close play married couple Mary and Mark Hughes, who rent a remote cottage with their young son after the tragic death of their six-year-old daughter in the movie.