Gaia, 16, is from a small seaside town south of Naples, but moved with her mother to be closer to the Caserta set. She tells Vogue that when she learned she was cast in the role, she wasn't clamoring to scream it from the rooftops, as one might imagine from a teen her age. "It's was a thing for me," Gaia, then 15, told the outlet. "A personal thing."

Given the fact that so much of the novels has to do with the relationship between Gaia's Lila and Margherita Mazzucco's Elena, what with their rivalries, competitiveness, support, and lifelong friendship at the forefront of the series, it was crucial to get the casting right — and My Brilliant Friend truly succeeded.

Since the actresses hadn't done much acting before, the audition doubled as an intensive acting workshop and a crash-course in the dialect.

"I fell in love with my character from the first scene I had to play, so I wanted to get that part at all costs," Gaia said of the lengthy audition process, which lasted seven months.

"I like the fact that she's observant and empathetic. But it's a difficult character to play, because she's very complex, she changes attitude in an instant. I was able to understand Lila only by acting her. She gives the appearance of being very strong — maybe if you read the book you might think she's bad, but that's not true, she contains a lot more: she has a fragility that she conceals."

Follow Gaia on Instagram to see more of the actress' life behind the scenes and stay up-to-date on her latest projects.

And of course, don't miss the chance to watch new episodes of My Brilliant Friend, Mondays at 10 p.m. on HBO.