Thomasin McKenzie on 'the job of a lifetime' in Netflix's Joy – and what Bill Nighy loves to get up to on set

There is something chameleonic about Thomasin McKenzie. So much so that you might not recognise her in her new film, Joy. But chances are she has graced your screen before, as a young Jewish girl hiding from the Nazis in Jojo Rabbit, or a Cornish fashion student who time-travels to the Swinging Sixties in Last Night in Soho. Next, the 24-year-old, who is wide-eyed and thoughtful with a softly spoken Kiwi accent, is on Netflix in Joy.

Joy is the true story of the development of IVF in the Seventies. McKenzie plays Jean Purdy, the third prong of the trio who helped the world’s first “test tube baby” to be born. “Jean was the first ever embryologist,” McKenzie says, “but she’d been kind of written out of the history of IVF.” For decades the pioneers of the treatment were remembered as a duo: scientist Robert Edwards and gynaecologist Patrick Steptoe, played by James Norton and Bill Nighy.