Nicole Kidman's Acting Was So Intense Meryl Streep Thought She Was Harming Herself

There's good acting... and there's acting so good you convince Meryl Streep it's real.

The 21-time Oscar nominee has revealed her "Big Little Lies" co-star Nicole Kidman's performance was so intense, she was believed she was harming herself.

"Right off the bat she did a scene where she had to do something really, really hard, like waking up out of nothing and going right into sort of a breakdown," Meryl told Vanity Fair of their very first day on set together.

"She did it over and over and over again, to the point where I thought, 'Is she being harmed in this process?'"

Meryl was so concerned she ran to the director to ask if he really needed another take.

"I mean, I've done this before with other people, because I know what it takes to do that," she said. "She was O.K. It's just like she has a kind of a placid, very quiet reserve that sits on top of this titanic power."

"I'm in awe of her. She's like a secret, soft Valkyrie with a spine like steel. She's very disciplined, but it's all in protection of a very tender self,' Streep continued.

"You forget that she's six feet tall, you know? But she is six feet tall, and sometimes she raises all of it up, and it's... wow. That's what you see in the end of this series. You see the full height of Nicole."

Kidman is Variety's cover star next month, on which she debuts a gorgeous new blonde pixie cut.

She revealed in her interview that she is on a group chat with the show's stellar female-led ensemble, including Reese Witherspoon, Laura Dern, Zoë Kravitz, Shailene Woodley and of course, the "very funny" Meryl.

"Look at the Friends cast, they spent all that time together—they're different because there are no men in our equation," Kidman said. "I mean, there are, but they're not on the group chat, let's put it that way."

Kidman also chatted about her two oldest children — Isabella, 26, and Connor, 24 — whom she shares with ex-husband Tom Cruise.

"Bella lives just outside London. You know, she really feels more English. We lived there for Eyes Wide Shut, Mission Impossible, and The Portrait of a Lady," she said. "They both had English accents when they were little."

Of her younger two children — Sunday Rose, ten, and Faith Margaret, eight, whom she shares with husband Keith Urban, she admits she is sometimes "unpopular" because of her parental policies.

"They don't have a phone and I don't allow them to have an Instagram," she said. "I try to keep some sort of boundaries."