The 48-year-old actress and her 57-year-old co-star are both excited to be returning for a third season of the hit HBO show - which originally ran from 2017 to 2019 - but the novel's author Liane Moriarty has been working on some new material.
She told E! News: "Nicole and I have been waiting. We're in waiting for Liane Moriarty. She's going to be turning in something very soon".
"We're back to the original author and we're going to go back to the original characters."
While the 'Legally Blonde' actress doesn't have much to share, she's keen to find out how the characters have developed. She added: "It's exciting, too, because I think the kids are probably a little bit older now.
"So that might add another element. I don't know yet, I haven't read it yet."
Nicole confirmed plans for a new season in November 2023, and over the summer she admitted she was over eager sharing the news at the time. In June, she told Vanity Fair: "I got excited. But we are now! We're moving fast and furious, and Liane is delivering the book. Yeah, and we're in good shape."
Meanwhile, the 'Perfect Couple' actress - who also starred alongside Laura Dern, Zoe Kravitz and Shailene Woodley in the show - insisted it's best to keep details about the new season under wraps until there has been actual progress. She said: "We need to shut up. There's this whole thing that you should never talk about something until you've done it.
"If you talk about doing it, it's the dopamine hit of doing it. You feel like you've done it. It's a scientific study." Back in January, Nicole confirmed there was a "timeline" for season three. Speaking to 'Entertainment Tonight', she said: "We are always cooking things up! We've got a timeline for it now."