"We all at some point lock our kid in a car by accident," the actress tells PEOPLE

By peoplestaff225
Updated April 18, 2016 01:30 PM

She’s got How to Get Away with Murder on lock, but Viola Davis sometimes still struggles with her real-life role of How to Be the Best Mom.

“When you have a child, you want to be a perfect mother. You feel like you have the absolute plan to be a perfect mother — and then you make a mistake, and we all make mistakes,” the actress, 50, told PEOPLE at the world premiere of Custody at the Tribeca Film Festival in New York on Sunday.

“We all at some point lock our kid in a car by accident or lose our kid in the mall for 30 seconds or more,” she adds. “I know one girl who’s a fantastic mother, [but] she lost her daughter in an aquarium for 30 minutes.”

Gilbert Carrasquillo/FilmMagic

Davis is mom to 4½-year-old daughter Genesis, whom she adopted as a newborn in 2011, and step-mom to her husband Julian Tennon‘s two children from previous relationships. And she’s learned that there’s no such thing as the perfect parent — and that’s okay.

“You have those moments: exhaustion, the stress of having an exuberant child, and you don’t want to be judged by your worst mistakes,” she says. “It’s a part of life, and it’s a part of what makes us who we are.”

Davis took that maternal understanding to her role in Custody, in which she stars as a judge presiding over a case after child services are called on a single mother (Catalina Sandino Moreno) when her kids’ teacher notices some cuts and bruises on them. (Hayden Panettiere costars as a defense lawyer.)

“I did the movie because it’s an indictment and also an exposing of a big issue in our culture,” adds Davis. “I wanted to be a part of that.”

— Jeff Nelson