Their reasons for not having children are varied, often deeply personal – and sometimes, like Mirren’s, circumstantial. The author Lionel Shriver is one of a growing number of women who are childless by choice, also known as “child-free”, or – as she puts it – an “Anti-Mom”. In response to criticism of her 2005 novel, We Need to Talk About Kevin, which some labelled “hostile to family”, Shriver wrote a series of articles justifying her decision not to have children. “I’ve had all the time in the world to have babies,” she said. “I am married. I’ve been in perfect reproductive health. I could have afforded children, financially. I just didn’t want them. They are untidy… they are ungrateful. They would have siphoned too much time away from the writing of my precious books.”