According to The Hollywood Reporter, she is set to play Princess Margaret in the drama's third season. She'll take over the role from Vanessa Kirby, who portrayed the royal in the first two seasons.
Season 3 will see the Netflix series undergo a cast overhaul to accurately reflect Queen Elizabeth transitioning from youth to middle age. As a result, Claire Foy will vacate her role as the British monarch and Olivia Colman will replace her.
Alongside Foy and Kirby, The Crown previously starred Matt Smith as Prince Philip, Victoria Hamilton as the Queen Mother, Jeremy Northam as Antony Eden and Matthew Goode as Margaret's first husband Tony Armstrong-Jones. The actors taking over these roles going forward have yet to be announced.
Season 2, which took place in the '60s, saw Queen Elizabeth facing war and several scandals, including the fall of Prime Minister Harold Macmillan, rumors of infidelity and her British troops being forced out of Egypt by the United States and the USSR during the Suez Crisis.
The first two seasons of The Crown are currently streaming on Netflix.