In the past the Oscar-winning actress has insisted that motherhood holds no interest for her and said she has "no maternal instinct".
But in a recent interview the 67-year-old admitted that she always expected to be a mother, reported The Telegraph.
"It was not my destiny. I kept thinking it would be, waiting for it to happen, but I never did, and I didn't care what people thought," she said.
The 'Queen' star has been in a relationship with Taylor Hackford, the American film director, since her 40s and married him in 1997. She is his third wife and he has two children from previous marriages.
Mirren said she "loves children" and enjoys being a stepmother, adding that it was more men than women who have questioned her about not having children.
"Women never gave me a hard time, anyway, it was only boring old men. And whenever they went 'What? No children? Well, you'd better get on with it, old girl', I'd say 'No!"