GUYTON -- It didn't take extraordinary acting ability for Kristy Garner and her family to be convincing in their roles. They just had to be themselves.

The Garners have parts as extras in “Instant Family,” a heartwarming, often funny film starring Mark Wahlberg and Rose Byrne. It has generated $104 million at the box office since its Nov. 18 release.

Like “Instant Family” director Sean Anders and his wife, Garner and her husband, Jamey, are the parents of three adopted children that they obtained through the foster care system.

“(Anders) wanted to write and direct a movie about the things they had gone through in the process,” Kristy said. “It’s based on their story. ... He wanted actual people who had adopted from foster care.”

Needing help to fill numerous roles in his movie that was filmed in Atlanta, Anders contacted the Georgia Department of Family and Children’s Services. 

“They sent emails out to everybody in Georgia who was a foster parent — like a casting call,” Kristy said. “I was kind of skeptical whether it was real or not because I had never done this before. Then, I thought, it came from DFACS.

“That, to me, made it more legitimate.”

The Garners applied for roles, sending photos of themselves as required.

“I didn’t hear anything for about a week but then they wanted more pictures of us,” Kristy said. “They said the director liked our initial stuff so we sent some more (photos).”

The Garners were one of 22 families who were chosen to participate. They were required to make multiple trips to Atlanta for filming, frequently with little notice.

“The first time wasn’t too bad,” Jamey said. “They gave us a notice of a week or two.”

Their first scenes, shot last March, took a couple of days to complete.

“It was an adoption fair scene,” Kristy said. “There were bounce houses, they had games set up and had picnic areas. It was an adoption fair.

“The kids just had to be kids for that.”

One of the Garner children, however, caught the eye of the casting director. He had nine-year-old Lucas in mind for a bigger part.

“They said they needed a kid to play an actual role, the role of kid about six years old,” Kristy said. “Lucas was eight at the time but he’s really small for his size and he looked six. They pulled about twelve or fourteen boys out, lined them up,  took pictures of them and texted them to the director on the set.

“The director chose three.”

Lucas was one of the finalists.

“We thought, ‘OK,!’” Kristy whispered while pulling her hands to her face in a show of excitement.

On the way to the set for a meeting with the director, Kristy coached Lucas as best she could.

“I’m like, ‘You don’t say anything unless he asks you a question. Then you answer it — and that’s it,” she said. “‘You answer exactly what he wants and just be truthful. When he tells you to do something, you do it and then you stop.’

“‘I said, ‘There’s no playing. It’s big-boy time.’”

Lucas delivered like a seasoned veteran. He thrived while his rivals struggled to stay focused on the task at hand, which, basically, was a test of their attention skills.

“(The director) kind of played ‘Simon Says’ with them,” Kristy explained. 

After Lucas was chosen, he was raced away to shoot a scene.

“That’s when I got filled in on what he was doing,” Kristy said. “The main characters — Mark Wahlberg and Rose Byrne — are at the adoption fair to try to meet a child they would like to adopt. That’s the whole point.

“Lucas is actually the first child that they are interested in at the fair. They go up to him and try to talk to him.”

Another set of parents, however, have their hearts set on Lucas’ character and interrupt the meeting.

“They say, ‘You need to back off! He’s ours!’ They are laying their claim,” Kristy said. “They have all these snacks and stuff. I just teared up watching the movie.

“Luke is front and center. It’s a cute, little, funny scene. I like it.”

As a preferred extra, Lucas ended up in additional scenes, including one in a courtroom.

All the Garners appear multiple times. Jamey’s head appears prominently in one scene with Wahlberg.

“Lucas, after we were headed home, asked, ‘Mom, am I famous now?’” Kristy said with laugh. “I told him, ‘No, baby. They movie isn’t even finished yet.’ Then he said, ‘But when it comes out, I will be famous?’

“I told him, ‘Babe, you are not one of the main actors but people will know you are in it and it will be cool.’ The he said, ‘Then I will be just a little bit famous.’”

Lucas and his natural siblings, 10-year-old brother Travis and four-year-old Hadleigh, were compensated financially for their movie participation.

“They got paid and it was nice,” Kristy said. “It’s in a bank account. We told them they could spend $50 (each), and that’s like $5 million to them.”

Kristy, an Effingham County Middle School teacher for 19 years, thinks the movie does a good job of exploring the many challenges of adopting foster children, including lengthy judicial proceedings. She and her husband served as foster parents for a decade, caring for 20 children.

The Garners saw the movie for the first time just before Thanksgiving in Pooler.

“We’ve only seen it twice,” Kristy said.

“My grandma has seen it three or four times,” said Jamey, a Georgia-Pacific electrician.

“Instant Family” drew an 81 percent approval rating from Rotten Tomatoes, an American review-aggregatiion website for film and television.

“It’s a good movie,” Kristy said.

“It’s got some cussing in it. I wish it didn’t have that.”

“Instant Family” is set to be released on DVD on March 5.

“We might give people autographed DVDs for Christmas this year — autographed ones,” Kristy joked. “They’ll have Lucas’ name all over them.”

Lucas, who got to rub elbows with some of the movie’s stars, actually received a fan letter from a family friend.

“He was pretty stoked about it,” Jamey said.

 Lucas would like to be in another movie. Kristy is keeping her eyes peeled for another opportunity.