Remember Cursing Toddler Pearl? Dad Adam McKay Says She's 'The Big Short' 's Secret Weapon

Sometimes 10-year-olds know what’s best – for movie audiences, that is.

While The Big Short director Adam McKay deserves much of the credit for his film’s Screen Actor’s Guild and Oscar-nominated success – particularly the way in which he cleverly presented the complicated story of the 2008 financial crisis to general audiences – McKay’s younger daughter Pearl played a key role in the film’s development.

Yes, that Pearl, the adorable cursing toddler from McKay and Will Ferrell’s viral Landlord video on their website, FunnyOrDie.

McKay says he runs all of his movie ideas by his family – wife Shira Piven, daughter Lily, 15, and Pearl, who is now 10 – but that Pearl’s seal of approval is a special one, particularly when it came to explaining the complexities of the film’s meaty subject: the ’08 mortgage crisis.

“When I can tell the story in three minutes, I know I’ve got it,” he tells PEOPLE. “I’ll actually tell my movie stories to Pearl as bedtime stories. I figure if I can engage her for 10 minutes, even if it’s a story where I change the specifics but where the macro story or spine of it are the same, so I started doing that [with The Big Short] and she said, ‘Dad, this is boring.'”

He continues: “I go, ‘Yeah, but think about it, we’re not in this house without a mortgage.’ ‘What’s a mortgage?’ So I explained it and we talked and talked and talked. Finally one day I was like, ‘They had all these mortgages and they bundled them together so they could sell lots of them, and they ran out of good ones.’ And she says, ‘Oh, so they put the bad ones in,’ and I thought, ‘Ding, ding, ding, I think I got it,’ so she was my final test case on it.”

Her best piece of advice? Don’t make it boring, dad.

“I was in my office working on the script with our consultant Adam Davidson, the financial journalist, and Pearl walked in,” recalls McKay. “‘What are you doing?’ she asks. ‘Well, we’re working on The Big Short,’ and she goes, ‘Daddy, don’t make this movie all boring and business-y.’ ”

Thanks to Pearl (plus McKay’s writing, directing and his A-list cast, which includes Brad Pitt, Ryan Gosling, Steve Carell and Oscar nominee Christian Bale) the film is not boring and it also got Pearl’s stamp of approval.

“Oh, she saw it,” says McKay. “There’s a side shot of a breast but it’s tastefully done, I didn’t care about that. And then they say ‘f—‘ a couple of times, so it was no big deal. She’s about to be 11, so it was not a problem for her but she liked it and then she explained to me what it was about and kind of got it, but I also don’t think you need to get every single detail as long as you get that bad s— was happening, these guys saw it, no one else did, they kind of got chewed up by the system but yeah, she was very funny.”

McKay says his daughter’s sense of humor also lends itself to great ideas for comedic sketches.

“She loves that show Dance Moms, so she wrote a sketch called Dance Dads, that was just indifferent dads reacting, ‘Yeah whatever, you look great, honey,’ dads on their phones,” he says. “I was saying we have to shoot that video, that would actually work.”

No matter her comedic talents and secret weapon ways, Pearl hasn’t let any of her celeb-esque status affect her in any way.

“The craziest is that Pearl now has been in two awards contender movies almost back to back,” McKay adds of The Landlord‘s continued role in pop culture. “She’s not really in Boyhood, it’s like a featured moment in the movie, they do it as a time lapse to show how Internet videos have gotten popular. They show the clip in there and then my editor put the clip in [The Big Short] and I said, ‘Hank, don’t put that in there, come on,’ and he says, ‘It works!’ and so I left it in for a screening and I was like, ‘You son of a gun, it does work.’ ‘I want my money!’ It fit alright, it’s in there.”

And what is Pearl’s reaction to all this notoriety?

“So now Pearl is just blasé,” he says, ” ‘[She says], of course my video is in every movie that gets award nominations.’ ”