Christina Hendricks ''froze'' when she was asked to play Charlize Theron's mother.

The 'Mad Men' star - who is only three months older than her 'Dark Places' co-star - has admitted she sighed with relief when she realised it was for a number of flashback scenes.

She explained: ''I walked on set and they had just lost their other lead to play Charlize's mom. They said 'Would you consider taking on this role?' and I sort of just froze.

''Yes [to play her mom]... In flashbacks.''

And the 40-year-old beauty has admitted she has tried her best to be ''professional'' in every job throughout her career.

Recalling one of her first days of work as an actress whilst on The Late Late Show with James Corden, she shared: ''I do remember one of the first days at work. You have that hose and you're trying to be professional. My boss had a big painting of himself in the salon and [the hose] slipped out of my hand.

''[Water] was on the client and on the painting. I was trying to get a handle on it. It was one of those bad shampoo girl days ...''