The Oscar-winning actress, who is also the executive producer of the award-winning HBO show, appeared on The Ellen Show on Tuesday.
During the interview Nicole told Ellen that her daughters Sunday Rose (10) and Faith (7) will have a cameo in the upcoming season.
"They were in as extras in Big Little Lies, which I've never told anyone," she said.
She also spoke about Meryl Streep’s addition to the cast. In the new season she will play Mary Louise Wright, mother-in-law to Kidman's character, Celeste.
Nicole revealed that Meryl joined the show before even reading the script.
WATCH THE INTERVIEW HERE:
Big Little Lies season 2 will air on HBO in 2019.