Dern stopped by TODAY Wednesday morning to talk about her on- and off-screen relationship with Woodley and the film that brought them together.
"Oh, it's full-on," Dern said of Woodley's use of her home as a crash pad. "She's there as much as she wants to be. My children love her so much, and they're (all) like family now."
Dern and Woodley forged their special bond while filming "Fault."
"We love each other — I mean this whole cast," she said. "We love each other so much, we had dinner every night, and we've become such a family. But Shai and I are very, very close. We felt really connected. I thought it worked particularly well because ('Fault' author John Green) so beautifully captured a mother-daughter relationship that's a very modern, progressive relationship — they're friends."
While there's a mother-daughter vibe to the off-screen bond between the actresses, it's not quite the way some might imagine it.
"(Shailene's) like a wise grown-up," Dern explained. "People are like, 'Oh, are you very maternal towards her?' I said, 'No. She's my mom, guiding me through my day."
But Dern also had paternal thoughts to share during her visit to TODAY. She delivered a birthday shout-out to her dad, actor Bruce Dern, who turned 78 Wednesday.
"The Fault in Our Stars" opens in theaters nationwide Friday.
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