Brand was born Mary Christianna Milne in Malaya but spent most of her childhood in England and India.

[1] She had a number of different occupations, including model, dancer, shop assistant and governess.

Her first novel, Death in High Heels, was written while Brand was working as a salesgirl, the idea stemming from her fantasies about doing away with an annoying co-worker.

In 1941, one of her best-loved characters, Inspector Cockrill of the Kent County Police, made his debut in the book Heads You Lose.

She is the author of the children's series Nurse Matilda, which Emma Thompson adapted to film as Nanny McPhee (2005).