Albert L. Ortega/Getty Deborra-Lee Furness and Hugh Jackman with their son Oscar (left) and daughter Ava (center)
The actress, producer and director sat down with PEOPLE virtually ahead of a Christie's sale benefitting her adoption nonprofit Hopeland and opened up about raising daughter Ava Eliot, 15, and son Oscar, 20, whom she adopted with Jackman, 52.
"It's so interesting being a parent, and they've both made me smarter than I think I ever could have been on my own," says Furness, 64. "But when you're a parent, you can't lie to them or yourself. They will shine a light on every one of your flaws, your Achilles heel, whatever. You've got to look at yourself."
"What I'm very interested in is epigenetics, and it's even more so when you have adopted children because I'm coming from my lineage of my mother, how she parented me, how her mother parented her, and I'm translating that to my children," she says. "But my children also have a separate lineage. So it's almost like we have more players at the table."
Furness says her kids' backgrounds along with her and Jackman's Australian culture are "just another little hurdle to jump over."
"We've got cultural differences in there, and I do believe these will play out generation after generation," she says. "So our family is just a little more late, I guess, at dinner time; a few more ancestors at the table."
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JB Lacroix/Getty Hugh Jackman and Deborra-Lee Furness
When it comes to embracing her children's cultural heritage, Furness says her family honored their different backgrounds.
"When my son was younger, he found out he was part Bosnian, so we went and got this Croatian/Bosnian cookbook and he was very proud to carry that around when he was 7 years old," she says. "My daughter has a Mexican lineage, so we've been to Mexico."
She continues, "We completely embrace the ancestors and the extended family; they're family to us. And it's in there, even though it's generational. It may be subtle, but it's in there."
"So it opens me up to be more open to, 'Ah, look at that probability,' because so many times, if it's a birth family, you'll have the same dislike — you both don't like mayonnaise or something," Furness adds. "You'll have that, but we have other different spices in there, so it can make it more challenging and it can make it more exciting."
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The actor will be celebrating his 23rd wedding anniversary with wife Deborra-Lee Furness in May
Furness' love of family has extended to her work on Hopeland, the New York City nonprofit she co-founded to prevent parent and child separation and ensure every child has a family.
"Every minute that a child is not in a safe, nurturing environment with a permanent family, damage is being done to them emotionally, physically and psychologically," says Furness. "That to me is just unacceptable. And society is measured by the way we treat our most vulnerable, so we, as a country, need to really step up."
Family "means you feel safe," she adds. "I always use the expression, 'All of us need to know that we're precious.' So, with family, you've always got that you're important in someone else's life."