Mahina Napoleon, a self-described “super major fan” of The Walking Dead, got the thrill of her life when she realized that she’d been cast as Ginny in The Walking Dead: Dead City.

“I was like, ‘oh my god, I used to watch this show and now I’m in it,” she exclusively tells In Touch. “It’s just super surreal.”

Two seasons later, Mahina, 15, reflects on some of her favorite on-set memories and how fellow costars Lauren Cohan and Jeffrey Dean Morgan helped her hone her skills as an actress.

“One thing I’ve learned is – especially with season 1, me not being able to speak – it taught me how to express my emotions without my words,” she shares. Fans remember that Ginny was largely nonverbal in the premiere season after experiencing the trauma of her father’s death.

“Lauren helped a lot. She taught me that over-expressing your emotions is so much easier, because you can always pull back,” the NCIS: Hawaiʻi alum continues. “But needing to show more emotion is a lot harder, so it’s always [better] to overdo in the scene because you can always pull back.”

She also says that Jeffrey was “the best” and his “hilarious” Negan-like vibe was “totally him too.” Despite playing a former big-bad of the flagship series, Mahina shares that the Grey’s Anatomy alum was a “really comforting” presence on set and he “also helped me a lot in the acting world.”

As for her favorite memories from working on The Walking Dead: Dead City, Mahina recalls a moment during the filming of season 2 when she, Lauren and Logan Kim just couldn’t get a serious scene down!

“I’m supposed to be really mad at Maggie and Hershel’s yelling at Maggie too, everybody’s just yelling at each other,” she tells In Touch. “It got to the point when we were needing to wrap up and everybody had the giggles … It was a super serious scene and we were trying to get it. We couldn’t stop laughing, but it was just really fun.”

Mahina previously spoke with In Touch about Ginny’s shift in her relationship with Negan after learning that he was the man who killed her father, as well as the internal changes the teenager has experienced as she’s wrestled with that revelation.

“I feel like you can definitely see the turn in how Ginny’s emotions have altered, like, completely,” she said at the time. “We can see how she’s accepted the fact that she really has nobody and she needs to figure out how to take on this world on her own.”

She also pointed out that this season, Ginny is “expressing a lot more” with her words, but she’s also continuing to express herself with her actions, such as in the Walker paddock fight scene in “Power Equals Power.”

“She is letting out so much anger,” she added. “And toward not only the Walkers, but to Maggie too.”

Watch The Walking Dead: Dead City on AMC on Sunday nights at 9 p.m. ET/PT or catch it streaming on AMC+.