Laura Dern decided to become an actor when she was just six. But it’s only now, with 55 films under her belt and as Big Little Lies returns to our screens, that she really feels free to ‘try anything’

To hear her mother tell it, it’s a miracle that Laura Dern exists at all. In the early 1960s Diane Ladd and her then husband, Bruce Dern, suffered an excruciating loss when their 18-month-old daughter drowned. The trauma was not just emotional but physical, and doctors told her that she would be unable have another child. But they were wrong, and the proof was Dern. One confounded doctor travelled to the hospital to witness “the miracle child”. From her home in Ojai, California, Ladd’s smoky southern voice over the phone ripples gently with emotion as she talks to me about her daughter.

The miracle child, now 52, grew up to be a great actor in her own right, sometimes even appearing alongside her mother. In 1991, Princess Diana was so taken by the idea that a real-life mother and daughter could play alternative versions of themselves on screen that she flew them both to London for a royal premiere of their garlanded film, Rambling Rose. Ladd recalls “pouring sweat” as she sat next to the princess. Dern was struck by the ways in which her host connected to her character. “She was empathy in cellular form.”