Credit: @willowshields / Instagram

With the final Hunger Games movie hitting theaters tomorrow, Nov. 20, we’ve been doing a lot of reminiscing about the series. And it turns out, we aren’t the only ones. As the franchise wraps up, its cast is also feeling nostalgic—especially Willow Shields, who was just 10 years old when she started playing the role of Katniss Everdeen's younger sister, Prim. Now 15, Shields has basically grown up on camera—and no one is more aware of that than the star herself.

“I’ve been looking back at photos from every premiere, from the first to the last,” Shields told InStyle earlier this week. “And for me, if you look at just the height difference it’s like, ‘What happened?’” She attended the Los Angeles premiere of The Hunger Games: Mockingjay—Part 2 on Monday, and a snap of Shields with her co-star and onscreen big sis, Jennifer Lawrence, from the night has been getting a ton of attention in particular. As soon as Shields saw the photo (pictured above) making its rounds online, she realized just how much she and Lawrence have changed since the original movie was released in 2012.

“At the L.A. premiere, we saw each other and took a really cute photo together in the green room,” Shields said. “I’ve already seen people sharing it online right next to the photo we took together at the first film’s premiere, and it’s absolutely insane to look at because we’ve both changed so much.” But while Lawrence’s transformation has catapulted her to superstar status, she’s managed to stay grounded, according to Shields. “She’s reached a level where she has such a huge fandom, but she manages to be super humble about it and just have a lot of fun."

Willow Shields and Jennifer Lawrence - Hunger Games Premiere
Credit: Getty Images (2)

As for her own transformation, Shields pointed out that it's a bit easier to spot in a picture. "As I was looking through photos, I started to laugh because my hair just kept getting shorter and shorter with each premiere,” she said. “At the beginning, I remember my hair was so long that it literally hit my waist. Everybody was telling me to cut it off because it just looked like I had a mane of hair as part of my outfit, and it was almost blending into my dress."

Over time, Shields just wanted a change. “For me, it was about growing up,” she said of ditching her long locks for a layered lob. “I felt that this was just a more mature look.” It was also an easy way to differentiate herself from Prim once the Hunger Games movies were over. “After you’re a part of a series for so long, I think it’s sometimes necessary to change your look,” said Shields. “That way, people don’t just associate you with your character.”

Jennifer Lawrence, Willow Shields
Credit: Franziska Krug

Of course, she isn’t the first young star to hit the salon for a shorter style after playing an iconic role. "We’ve seen people like Emma Watson cut off all her hair after Harry Potter,” said Shields. "It’s something that some people feel the need to do after finishing a series, and I’m so happy I did because I love it.”