In the U.K., there is a sort of obsession with class.

I did all sorts of jobs after drama school - working in a bar, as a teaching assistant. I probably learned as much from them as I did at drama school.

I grew up listening in awe to stories of their wartime adventures. My granny, Joan, was a journalist and wrote amazing letters to my grandpa when he was a prisoner of war, while my nana, Mary, was a Land Girl, then a Wren. They were so independent, resilient and glamorous.

In a way, it's good not to be recognised as much off screen.

There's something about wearing clothes that your great-grandmother might have thought were nice that makes you look older.

There is no way I'd have wanted to live in the Twenties. It was really crap for women.