“The root of the female midlife crisis isn’t that we’ve had enough of our partners or children, but that we’ve had enough of ourselves”

I am on a film set in Smithfield, east London. Emily Watson, Oscar-nominated screen star, is walking towards me with a smile. We are just two of a crowd of people in a grand building called Haberdashers’ Hall, where the most important scene of the BBC adaptation of my novel Apple Tree Yard is being filmed. The scene appears towards the end of episode one. The main character, Yvonne, played by Watson, is at a champagne-fuelled leaving do for the head of department of a university where she does some freelance work. Yvonne is a high-achieving, fiftysomething research scientist, with a husband and two grown-up children and a beautiful suburban home. At the beginning of this episode, she has been giving evidence at a House