Big Little Lies” has major star power, but the question of who would get which role was settled pretty quickly. Nicole Kidman wanted to play Celeste, the picture-perfect wife with a dark secret, from the start — a move that co-star/co-executive producer Reese Witherspoon agreed was a natural fit. “I actually thought she was perfect, and it’s a challenge,” Witherspoon says. “That’s a big undertaking.”

But Witherspoon wasn’t set on any particular role. Perhaps, she thought, she’d play Jane, the single mom who’s new in town. (Shailene Woodley ultimately was cast in that role.)

Enter writer David E. Kelley. “To me, when I read the book, I just immediately saw Reese as Madeline, no question,” he says. “Then, when Reese and I met, and I mentioned that she was Madeline, she did give me a look like, well, that was news to her.”

Photo: Mark Williams & Sara Hirakawa; Grooming (Vallée): Sara Denman at Celestine Agency; Wardrobe (Witherspoon): Petra Flannery at Two Management; Sweater: Lanvin; Jeans: Mother; Jewelry : Jennifer Meyer

Witherspoon admits she was taken aback by the suggestion that she was right for the character of the fast-talking helicopter mom who can be a bit overbearing. “I was like, ‘I am not! You don’t know me! I am not like that woman! I don’t know if I should be insulted!’”

But Kelley insisted she would “eviscerate” the character. (Director Jean-Marc Vallée, for the record, thought Witherspoon could play either Madeline or Celeste.)

Witherspoon conceded, and the first day on set, she was convinced. While filming a scene where she’s introducing Jane to the other parents at school, the part of Madeline came naturally, she recalls. “I got on set in that outfit, and we had to do that long walk, I just started doing it. And I was like, ‘Oh, this just feels like a pair of gloves; they just fit perfectly.’”

Now she admits it was the perfect choice. “I always love playing characters who are talking but aren’t listening to what they’re saying,” she says.