Writer–director Louise Archambault balks at the mention of Sean Penn. He might have bagged an Oscar nomination for 2001’s I Am Sam, but his showboating performance will always and forever symbolize Hollywood’s syrupy approach to the developmentally challenged.

Back here on Earth, Archambault presents a much smaller and more naturalistic view of a special-needs character with Gabrielle, a film that only seems modest when you factor out that its lead, Gabrielle Marion-Rivard, was born with Williams syndrome, a genetic disorder that tends to be characterized by elfin facial features and a highly gregarious nature.

Marion-Rivard is luminous in the role.

Archambault refers to her “magical presence” more than once during a chat with the Straight at the Whistler Film Festival, but Gabrielle is never condescending or sentimental about its subject. Simple challenges become aggravatingly large for a young woman trying to cope with family instability, dawning sexuality, and a desire for independence, all of it captured in photorealistic style by Archambault’s camera.

In directing Marion-Rivard, Archambault came to know this foreign world intimately.

“Emotionally,” she says, “she’s much stronger than I am. So true, so honest, and she’s there. But, let’s say, ‘Okay Gabrielle, go get the keys on that table, and go out the door.’ For us it would be, you know, one take. For her it could be 20 takes, and she’d be stressed. So I needed to find the path in her mind, you know?”

Archambault continues: “In her syndrome, she’s very expressive—we call it theatrical behaviour—but for cinema sometimes it’s just too much. So I did some workshops with her, and she could be toned down, her expressions and stuff, but it was dull. So I had to find a way to have her in that character but with that magical light. So I did let go of many things. Not just with Gabrielle but with the other nonprofessional actors.”

Marion-Rivard also possesses perfect pitch, another common facet of Williams syndrome, and the film turns on her involvement in a choir for the disabled. That’s where she moons over Martin, played—in an equally impressive achievement—by the decidedly unchallenged Québécois actor Alexandre Landry. Their frank scenes together are a model of sensitive filmmaking, and if Martin’s steely and overprotective mom provides the film with some necessary conflict, Archambault’s risky venture seems to have won everybody’s approval in real life.

“What I can say is that people who inspired me, parents involved in the film, they were my first public, actually,” Archambault says, softly. “And they were, like, ‘Wow, it’s as if you were in our families, you know?’”

Meanwhile, Robert Charlesbois evidently added some perspective to a project fraught with pitfalls. When he showed up for his first day of shooting—Gabrielle’s choir performs “Lindberg” with the Québécois singing legend in the film’s soaring climax—Archambault decided to wing the entire scene without rehearsals.

“So I went out into the hallway, and I said to Robert, ‘I’m going to improvise when you come in,’” she recalls. “And he was, like, ‘Oh yeah, is my hair okay?’” It seems that we all need a little extra care and attention from our director.