Perry, who died unexpectedly in March at the age of 52, played an actor on Lancer, the real-life late '60s Western TV series Bell and Leonardo DiCaprio's characters appear in during Once Upon a Time. Perry was not the only late star Butters had the opportunity to work with on the film, in which she steals scenes as a child prodigy who must teach fallen actor Rick Dalton (DiCaprio) to get his groove back.

Burt Reynolds, who originally was to play ranch owner George Spahn, attended a cast table read before his death last September.

"We were all talking and he said, 'The 12-year-old in me wants to marry you,'" Butters recalls with a laugh. "And my mom yelled from across the room, 'I approve!'"

By the time Butters got to that star-packed table read, which also included Brad Pitt and Margot Robbie, she already had her part memorized, as Tarantino had her audition with her actual lines from the film. To make her comfortable during filming, the director would get down on the ground and speak to her on her level.

"He was really nice and went that extra step to direct me," Butters notes.

Though she'd never heard of the filmmaker before auditioning, Butters eventually formed a bond with Tarantino that continued after the shoot, with the pair becoming pen pals.

Butters first met DiCaprio at the Once Upon a Time table read, and later she spent time running lines with the actor at his home, where the Oscar winner welcomed her and her mother. DiCaprio gave Butters tips about how saying a word slightly differently — or changing a facial expression just a little — could do so much for a performance.

One moment in the film called for DiCaprio's Rick Dalton to throw her character off of his lap, and the older actor was concerned for Butters' well-being.

Recalls Butters: "He was so very nice that he said, 'I'm going to ask you every time if you're OK, because I would never forgive myself if I hurt my princess.'"

Butters also comes from an industry family; her father is animator Darrin Butters, who has worked on Disney projects such as Tangled (Julia's favorite) and Frozen. Though this is Butters' highest-profile project yet, she has been working for years. She modeled as a baby and transitioned to acting with Criminal Minds after a friend of her mother's penned a role for her on a 2014 episode of the CBS procedural. She can currently be seen on the ABC sitcom American Housewife. Butters still hasn't seen all of Once Upon a Time and likely won't for some time. As she noted Thursday via a Twitter account managed by her parents, "It's rated R. I'm only 10."

July 28, 5:53 p.m. A previous version incorrectly stated that Lancer was a fictional TV show. THR regrets the error.