She may be just over 5 feet tall, but Hilary Duff casts a long shadow in Hollywood, where the teenage star of “Cheaper by the Dozen,” “The Perfect Man” and “Cinderella Story” is already one of the hottest young actresses in town — as well as a one-woman empire with a clothing line (Stuff) and a successful recording career.

“As a kid, I did ballet and gymnastics like my older sister Haylie,” says the 20-year-old Houston native. “Then we did some acting classes and local plays, and we’d bug our mom to take us to auditions, so what began as a hobby got more and more serious.”

After a notable turn in the 1999 TV show “The Soul Collector,” Duff got her first big break, starring in the hit Disney series “Lizzie McGuire,” which spawned a hit movie as well. “That show really paved the way for me to go on to do other projects and also introduced me to the pressures of instant fame,” she recalls. “After the second episode, I couldn’t even go to the mall — it was total insanity. I didn’t know how to deal with it. There’s just no way to prepare yourself, and it hasn’t stopped since then.”

But the multitasking Duff has learned to cope, “mainly by just focusing on my career and working really hard,” both on her acting and music (she recently released her fourth solo album, “Dignity,” which she co-wrote). “But there’ve been sacrifices,” she admits. “I’ve missed out on doing typical teenage stuff with friends. For the past four years, I’ve also been touring musically, and while I feel the sacrifices have been well worth it, I’d now like a more normal life, so I’ll focus more on my acting.”

She returns to the screen with Sundance-bound “War, Inc.,” which she describes as “a very different character for me.” The shoot took her all the way to Bulgaria and gave her an opportunity to work with Ben Kingsley and John Cusack.

“It was scary but great,” she says. “As I get older, I want to challenge myself more and take more risks, but I don’t like to plan too much ahead. I don’t want to burn out. I always want to enjoy what I do.”

Recent breakthrough: Duff’s third album, “Dignity,” debuted strong and showcases a grittier edge for the triple threat.

Role model: “Drew Barrymore, Cate Blanchett — I admire their careers and the way they’ve stayed away from gossip and made personal lives for themselves.”

What’s next: “I’m doing another small indie drama, ‘Greta,’ with Ellen Burstyn, that I’ve pursued for three years.”