If “Doubt,” the critical and popular hit by John Patrick Shanley now playing Broadway’s Walter Kerr Theatre, is essentially a tug of war between Cherry Jones, who plays the resolute nun Sister Aloysius, and Brian O’Byrne, as Father Flynn, the charismatic, modern-thinking priest Aloysius suspects of molesting a young boy, then Heather Goldenhersh is the rope they strain at.

Ms. Goldenhersh plays Sister James, a novice at the St. Nicholas Church School in the Bronx, where the play is set. Hers is the soul both nun and priest fight over; without it, their arguments lack a sympathetic sounding board. During “Doubt’s” off-Broadway run, Ms. Goldenhersh was commended for her performance, but when the play reopened on Broadway, many critics recognized that her work was as complex and rich as that offered by Ms. Jones and Mr. O’Byrne. Some now expect she – along with Ms. Jones and Messrs. O’Byrne and Shanley – will find a place on the ballot when the Tony nominations are announced May 10.

In fact, whether or not she’ll get that nod may now be an easier matter to guess at than the puzzle at the heart of “Doubt.” And so, Tony Schmony: Let’s chase the truth every audience would like to know. Does she think that Father Flynn is innocent?

“According to the story Mr. Shanley wrote, Sister James does,” hedged Ms. Goldenhersh. Yeah, yeah, but does she? “If I were in church and heard his first sermon in the play, about how doubt can be a bond, and that it’s okay to despair – as Heather, I would probably.” She mocks swooning (something every actress should be able to do).

“It very comforting and human,” she said. “I know there are some sects of Christianity out there where worry is a lack of faith and is a sin. You can certainly beat yourself up for that. I used to.” What Heather Goldenhersh means is that – long before she ever encountered Mr. Shanley and his shades of gray – she had personal knowledge of how one can be torn apart by religious certitude.

In the early 1990s, when – at the age of 18 – she was suddenly thrown into the intense world of Juilliard, the unformed St. Louis native fastened onto the devout Fundamentalist Christianity practiced by her mother’s side of the family. “I came into school and was kind of shaky in my skin, and searching for some kind of stability,” she said. “I was pretty religious and went to church nearly every Sunday.”

Needless to say, she found few other Christian soldiers among her fellow acting students. “I felt like a real alien,” she said. “Most people were like I’m going to stay up all night and drink and go crazy.’ I’d had examples in my family of wildness and chaos, so I tried to go the opposite way. And that was difficult. I felt like I was trying to lead this cloistered, spiritual life.

“Meanwhile, I’m in drama school! Hedonism! Everyone’s just exploring what it’s like to be human. And there was my Jewish father, and he’s seeing me get really caught up in another religion. It was, like, this thing between us. He says it didn’t really bother him, but he was worried for me.”

All told, her flirtation with orthodoxy lasted roughly six years. After that, she “hit a wall.” In the time that immediately followed, she made up for lost youth and “partied like the rest of them.”

Now 32, she’s philosophical about that period of her life. “It was my path to be an 80-year-old when I was 20.” How old is she now, inside? “Maybe I’m 14. I’m going back a little bit.”

Her experience helped inform her portrayal of the morally and emotionally flummoxed Sister James. Nonetheless, the actress confessed she was surprised she clicked with Mr. Shanley’s moral parable. “It’s strange,” she said. “Coming into the first rehearsal, I was very nervous, because this felt like a really straight play. In modern work, I’d been used to more kooky characters.”

This comment raised neither of her interlocutors’ eyebrows. For on first impression – and despite all the deep-dish spiritual mishegoss mentioned – Heather Goldenhersh comes off as something of a kook herself. Her brown button eyes and crooked smile radiate an appealing goofiness. And any whiff of actressy vanity is thoroughly undercut by a tomboyish outfit of jeans, button-down shirt of mannish cut, and a baseball cap (“Jack’s Stir Brew Coffee”), its visor squeezed into a right angle.

James Calleri, a casting director at Playwrights Horizons who has hired her several times, is well acquainted with this odd combo of the naive and the knowing. “There’s a little bit of what looks like wide-eyed innocence,” he said, “but at the same time she digs in and pulls things up. I hire a lot of Juilliard actors, and sometimes I think when they get out they’re a bit stripped down. She got out of that. She was still very clear about who she was. She didn’t sound like everybody else.”

The sound Mr. Calleri refers to is Ms. Goldenhersh’s distinctive, somewhat sibilant accent. Wielding on stage, it lends Sister James a kind of flustered simplicity. In private conversation, her voice betrays more notes of sandpaper and cigarettes, and her rhythms are lazier. In the course of a 40-minute interview, she exercised the drowsy rejoinder of “Yeeeaaah … yeeeaaah” roughly 27 times. It is a thought-capper she perhaps learned from her parents, whom she described separately as “a wild girl,” and “a bit of a troublemaker” and later summed up jointly with: “They were both hippies.”

As Ms. Goldenhersh’s curtain time approached, the newly laundered hat for her costume was delivered to her dressing room at the Walter Kerr. “Ooh, fresh bonnet!” she enthused. The headgear precludes extensive fussing with her curly brown locks, which is fine by her. “On TV auditions, and things like that, I don’t recognize myself when I do my hair up. Conventional, you know.”

She finds comfort, too, in the rest of the outfit. “In the habit, I could probably gain like 50 pounds and be all right.”

Perhaps tiring of Sister James’s less-than-fashionable version of basic black, she tried for a bit of glamour at the production’s Broadway opening night party, donning a dignified dark dress, fur stole, and “sparkly shoes.”

“I wanted to look like a lady,” she said. But that backfired in a surprising way – she got an angry letter from PETA, which spied the fuzzy accessory. That rather floored her. “I didn’t think anybody’d notice. Who am I? It’s not like I’m people, or anything.” That remains to be seen.

The Tony award nominations will be announced tomorrow at 8:30 a.m.