The 42-year-old actress, who was reared in the UK but was born in the US, has been promoting Horizon: An American Saga, her most recent film, which was helmed by Kevin Costner.
Miller, who will appear in both this film and the next installment, plays East Coast resident Frances Kittredge, who relocates to the Horizon colony with her husband and two children.
Miller chose a pale blue floor-length gown, while Marlowe, 12, made her red carpet debut in a white dress with a huge pale pink bow around her waist.
In 2012, Miller gave birth to Marlowe, whose father is Tom Sturridge, 38, who stars in The Sandman.
