Sarah Steele of ‘The Country House’ finds comfort in her characters

“Who are you?”

It’s a line Scott Foley, playing TV star Michael Astor, delivers to Sarah Steele’s teenage character Susie Keegan in the new Donald Margulies play “The Country House” at the Geffen Playhouse after Susie delivers a diatribe of truth: The handsome Michael’s fans watch his productions only to see him rather than his acting chops.

Steele’s character in the play — which is directed by Daniel Sullivan and moves to Broadway in October — exists as a beacon of normalcy in a dysfunctional family of overdramatic actors. In a way, so does Steele, in a business in which young starlets work to brand themselves alongside their talent.

Even though she exhibits the confidence her character Susie displays on stage, Steele, 25, confesses that Susie would handle this interview much better.

“To be honest, this makes me much more nervous than playing a part,” Steele says. “I actually feel more comfortable when I can hide behind someone else’s words, particularly someone like Donald Margulies. A Pulitzer Prize winner’s words. That makes me less nervous.”

Steele brings her characters to life with natural gestures and speech. Playing Susie, the only member of a family of actors that isn’t interested in “the business,” she drapes herself on the set’s easy chair, casually eating an apple while engaging in Margulies’ sharp dialogue with Blythe Danner, who plays her grandmother.

In the interview, however, she nervously toys with her necklace — a gift from Dakota Fanning, costar on her latest film, directed by Gerardo Naranjo (“Miss Bala”) and set to be released next year — as she second-guesses her own answers.

“Eric Lange, who is in our show, told me that he feels that I’m like a 40-year-old woman trapped in a 25-year-old’s body,” Steele said. “I don’t necessarily feel that way, but I do feel more comfortable with older people generally, and I think maybe that’s why I get these roles.”

Steele has found herself in a series of supporting roles as the younger character who often demonstrates more maturity and wisdom than her older counterparts. Audiences first saw her opposite Adam Sandler in 2004’s “Spanglish” as Bernice, his character’s daughter who is navigating her awkward teenage years.

After entering the world of Hollywood at 15, she retreated to her native Philadelphia with a sharpened acting goal: theater in New York City. She deferred attending Columbia for a year to work in her first off-Broadway play, “The Prime of Miss Jean Brodie” with Tony Award winner Cynthia Nixon, and earned an English degree while continuing to perform.

“I needed the time to go to college and spend years with people who aren’t in the business and become a person on my own in order to be the person that I am and the performer that I am,” Steele said. “I wouldn’t give that up to be in blockbusters or have more money.”

Steele’s next major film came in 2010 with the Sundance indie effort “Please Give,” directed by Nicole Holofcener. Starring alongside Aubrey Plaza in 2013’s “The To Do List” brought her together with a young cast and audience, but “branding” herself as a star — like Plaza, who has a personal Twitter following of 683,000 — has never appealed to her.

“Oh my God, no!” she blurted. “That is actually one reason I was very impressed with Aubrey Plaza when I worked with her. That is something I could truly never do.”

Though film and TV find their place on Steele’s résumé, it’s well-written characters that draw her rather than a starring role in a blockbuster. Most of those parts, she says, seem to be in theater.

“I think I’m a character actress at heart, and I think my work is character work for the most part,” Steele says. “I’m not the lead of any films — which is not to say that I wouldn’t ever want to be, it is just to say that hasn’t been my path.”

Steele resists comparing her career to the trajectory of actors she admires, yet she dotes on the work of Annette Bening. Revealing her true mid-20s self, she references a recent BuzzFeed article on Martha Plimpton, an actress who similarly enjoys well-written stage roles for women.

“One of the things she said in it that really spoke to me was ‘I don’t have the face of a movie star, I have the face of a character actress.… I think what’s going to happen to me is I’m going to have great theater roles and sort of make money in television and film,’” Steele said, paraphrasing Plimpton.

“I really identified with that. Because that’s how I felt my career has gone so far, is that the great roles that I’ve played have been in theater, which is not to say that’ll never happen to me in TV and film, but my experience has been thus far that the great roles I’ve gotten have been in the theater. I wouldn’t mind continuing along that path — it’s what I like best.”

haley.goldberg@latimes.com