Sadie Sink Feels 'More Comfortable' with Herself at 20 — But Not 'Quite Like an Adult Yet'

Sadie Sink ushered in a new decade earlier this month when she bid her teenage years farewell.

"It feels weird saying 20! There's no 'teen' in it anymore," says the Stranger Things star, who modeled peach makeup for PEOPLE's The Beautiful Issue.

"Because I started so young, my childhood felt somewhat fast tracked," she explains. "I think a lot of aspects of my life have been pretty adult, but I'm still playing a teenager. So I don't feel quite like an adult yet."

While she may not feel her age just yet, Sink notes that she has "recently felt a lot more empowered."

"I'm proud of how much more comfortable I've become not only my personal life, but also in my professional life," she says. "I think I was really timid when I first started out, because everything was really new and scary, so it's been nice as I grow up to not be as timid. I think I can speak my mind a little bit more."

Over the years, the actress has also learned to "work through" her nerves.

"You just have to keep pushing forward and then eventually be like, 'Why was I so worked up?' I feel like I've relaxed a little bit," she says.

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Because Sink began her acting career so young, she believes "there are a few steps that I missed along the way" — namely, participating in school musicals.

"I've always wanted to do one and I was working and I couldn't," says SAG Awards nominee. "Maybe Into the Woods or something [Stephen] Sondheim."

Before Sink returned to work to film the upcoming fourth season of Stranger Things, she says she embraced life's simple pleasures during the pandemic.

"Spending time with family is big. It's just good for the heart," she explains. "Also walking has been really good — going on really, really long walks and getting over 10,000 steps a day. That's been nice."

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As self-care pertains to beauty, Sink hasn't taken on a multi-step skincare routine or found a favorite face mask. The actress says her normal makeup routine consists of "pretty much nothing."

"If anything, I'll just brush up my brows or put ChapStick or lipstick on," she shares, adding that with age, she feels "free to try new looks."

But while the young star may feel comfortable experimenting with beauty products, she also knows to give herself some grace and not "stress about it too much."

"It's not that big a deal," Sink says of making the occasional beauty blunder. "Don't be too scared of it."

For more Sadie Sink, pick up The Beautiful Issue of PEOPLE, on newsstands now, or subscribe here.