The three-time Oscar winner joined the cast of the Emmy-winning HBO series as Mary Louise Wright, the mother of Perry Wright (played by Alexander Skarsgard in Season One) who wound up dead at the end of the first season. The grieving mother wants answers and can tell the Monterrey 5 know more than they're letting on.
At the New York City premiere for Season 2, Witherspoon who also serves as an executive producer joked to reporters that Mary Louise and Madeline's relationship "gets better and better and worse and worse."
"[Mary Louise] has pretty much conflict with everybody in the whole show," she teased. "And [Meryl's] fabulous."
Besides dealing with an aggressive Mary Louise, Witherspoon says her character is also dealing with issues in her marriage and the weight of the secret the women are keeping from their loved ones. "I'm trying to keep everyone together and make sure no one spills the beans," she said.
As for adding Streep to the TV project, who already has three Emmy awards, Witherspoon said: "It's a dream come true."
"She spent the collateral that she has in her career on a show like this means the world to us," she added. "There's nothing better than female partnership."
Women certainly lead in front and behind of the camera in Season 2 much like the first season -- Andrea Arnold directed all seven episodes, Nicole Kidman (also plays Celeste Wright), Liane Moriarty (author of the book), and Bruna Papandrea returned as executive producers, and all of the main actresses signed on again to reprise their roles.
Witherspoon told Fox News of working predominantly with women: "It was just different. I never really had that opportunity in my career. Laura [Dern], Nicole and I would look around and go, 'I can't believe we have so many scenes together, that we have so many lines with each other, that we're exploring our relationships.'"
"Hopefully that will create more shows that do that same," she added.
"Big Little Lies" premieres June 9 on HBO.