Photograph by Robert Nethery; styling by William Graper.

At the bottom of Lucia Santina Ribisi's email signature, it says, simply, "Teen Artist." It's a charming sign-off, but although she is still only 18, Ribisi, who is the daughter of actor Giovanni Ribisi, has probably outgrown that modest description. For much of January going into February, she was locked away with an assistant in a studio rented for her by Saint Laurent, working on a white-on-black mural of spindly palm trees that would serve as the backdrop of Hedi Slimane's Fall 2016 show in Ribisi's native Los Angeles.

It was her second collaboration with Saint Laurent, after Slimane discovered her work last year and plastered Ribisi's glittery "Baby" text painting (from her "Pet Names" series) on Saint Laurent bombers, surfboards, and backpacks for spring 2016.

"It's hard to act like a teenager anymore," Ribisi said recently. "I want to expand my arms as far as I can reach, and I feel like I can do that now with the exposure I've gotten from this collaboration." She gave a little sigh. "A lot of the people around me are trying to get me to slow down. My friends are always like, 'What's your problem? I never get to see you anymore.' But my work is my priority."

Whereas some take a gap year to spend money overseas, Ribisi took a year off after learning of the first Saint Laurent collaboration to focus on her art. She began making performance and video pieces; she painted her friends; and, true to cliché, she even traveled across Europe—although she documented her wanderings in a video diary for *L*'Officiel. "I'm working everywhere I go," she said.

With her round eyes and heart-shaped face, Ribisi appears innocent, but in her work she has begun tackling more mature subject matter, from feminism to sexuality to gender identity to her parents' fraught relationship. She even made a zine, in collaboration with Autre magazine, consisting of love letters that her mother, Mariah O'Brien, wrote to her father when she was pregnant with Lucia. "I have very little previous knowledge of them as a couple," she said of her parents, who separated when she was four. "A lot of my work has been about growing up in a tumultuous situation."

(After initially giving his approval, although not without deep reservations, her father asked Ribisi in the end not to go through with the publication of zine, right before it was set to be distributed during the L.A. Art Book Fair last month.)

Ribisi hasn't forsaken being a teenager entirely. She still makes most of her art in her bedroom, to the point that she had to make a curtained canopy for her bed "to separate my work from my sleep," she said.

The work, of course, is not the typical teen fare: "I'm making an intersex pillow that is 18 feet long. It's a penis that goes into a vagina, all in one piece. It's big enough that it wraps all the way around my room." She laughed. "It's pretty abstract."

Take a tour of Ribisi's home here:

Photograph by Robert Nethery; styling by William Graper; hair by Anna Lyles for Macadamia professional at atelier management; makeup by Stevie Huynh at D+v management; photography assistant: Steven Gabriel; fashion assistant: Sarah Kretzu.