Nicole Kidman's Teen Daughters 'Really Fangirl' Over Her “Family Affair” Costar — But It's Not Zac Efron

The actress is mom to daughters Sunday, 15, and Faith, 13, whom she shares with husband Keith Urban

Nicole Kidman's teen daughters were so excited their mom signed on for her new movie Family Affair — but not because she was costarring with Zac Efron.

Speaking to Entertainment Tonight at the film's Los Angeles premiere on Thursday, June 13, Kidman, 56, shared that her daughters Faith and Sunday, whom she shares with husband Keith Urban, "really fangirl over Joey [King]. Which is nice, right? They've grown up with Joey."

Kidman plays costar Joey King's mother in the film, which shows the actress pursuing a May-December romance with Efron, 36.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Related: Nicole Kidman on Having 'Incredibly Loving' Daughters Support Her at AFI Awards: 'It's Beautiful' (Exclusive)

In April, Kidman was honored at the 49th AFI Life Achievement Award Gala in Hollywood, California. When asked what it was like to have her daughters witness such special moments in her career, Kidman jokingly told PEOPLE, "You'll have to ask them."

"I think they're just like ... they want to get started on their own careers," the actress continued of her daughters, whose attendance at the gala with Kidman and Urban marked their red carpet debut.

"They are here to support me, and they're very, very supportive and incredibly loving," she added.

Although they attended the award gala in support of their mom, Kidman's daughters did have one particular part of the night they were especially looking forward to, she said.

"We're going to do a post wrap-up at the house late, late tonight," the Big Little Lies actress explained, adding, "There's a party afterwards, and they're like, 'Oh, there's a party?' "

"That's what they're excited about," she teased.

In January, the actress told Vogue Australia that her daughter Sunday recently sat down and watched Kidman's HBO show, Big Little Lies for the first time.

Kidman told the outlet that playing Celeste — a role that's earned her an Emmy, a SAG and a Golden Globe — has garnered her a lot of attention and thanks, but she was most stricken by her daughter's response.

"She has a very good understanding of things, and life, so she was hand-held through it," Kidman said, noting there were still scenes where she instructed the teen to look away.

“And she was like, ‘No. There’s no more discussion. The third series has to happen… I’m sick of the talk. Sick of circling it. Just get it done,' ” Kidman laughed. “You need a teenager to go, ‘Enough. Just do it.’ "

For more People news, make sure to sign up for our newsletter!

Read the original article on People.