NEW YORK - In the middle of a whirlwind week this month, Rose Hemingway finished stage-smooching with Daniel Radcliffe in a matinee performance of How to Succeed in Business Without Really Trying and took her final curtain call. Leaving behind an array of mostly deep-pink '50s-style costumes, she donned street clothes and dashed outside the Al Hirschfeld Theatre on 45th Street.

The folks from Mount St. Joseph Academy in Flourtown were waiting for her.

"The look on her face when she came across the street to see the Mount people who came to see her - she was thrilled," says Sister Kathleen Brabson, president of the girls' academy whose stage Hemingway, Class of 2001, had graced through high school.

Now, a decade later, what Hemingway dreamed on that stage is real. "I got to see it come true," she says. "I feel very blessed."

She's on Broadway.

The 50-year-anniversary revival of How to Succeed officially opened Sunday night, with Radcliffe, who has spent much of his 21-year life portraying Harry Potter on screen, as the musical's charmingly conniving corporate climber. Hemingway is the gal who chases him until he catches her, and veteran actor John Larroquette (TV's Night Court, film's Stripes and JFK) is the easily snookered corporate chief they both work for. Larroquette, like Hemingway, is making his Broadway debut.

The show is arguably the cheeriest, most charming Broadway revival since The Pajama Game five seasons back, and Radcliffe is especially surprising as a dancer, if not much of a strong singer. Hemingway is adorable, with a classic Broadway voice that gives her character oomph and a solid stage presence that gives it life.

A brunet mezzo-soprano with sparkling eyes, a big smile, a winning personality, and a passion for musical theater, she didn't come to Broadway through regional professional stages - in fact, if you're a Philadelphia theatergoer, it's unlikely you've seen her unless you caught the national tour of Mamma Mia! two years ago at the Academy of Music, in which she played the role of the about-to-be-wed daughter.

Instead, her trajectory (she probably wouldn't call it that, given three years of New York waitressing and bartending) was through Mamma Mia! and a Los Angeles production of Parade by Britain's Donmar Warehouse directed by Rob Ashford - the director-choreographer of How to Succeed.

Hemingway, 27, recently took the last name of her husband, Geoff, who played her fiance in Mamma Mia! and, yes, is a distant relation of you-know-who; they were married nightly on stage, then for real last November at Mount Airy's Holy Cross Catholic Church.

Before that, she was Rosemary Szczesniak, the sixth of nine children who grew up in the Mount Airy home where her parents still live. Unwavering fans, they were in the audience at the first How to Succeed preview, a month before the opening. Hemingway says her mother told her, "The second you walk on that stage I want to be there."

Her acting life began as a young grade schooler at the Water Tower recreation center in Chestnut Hill, where she was taking gymnastics and the center's acting group "was doing Peter Pan and needed to fill out the show, and asked if anyone wanted to be a flipping pirate. I did - and I fell in love."

This, she says, surprised none of her sibs. "I was always the obnoxious sister who wanted to be the center of attention." She found her outlets: the Water Tower shows all through grade school, then Mount St. Joseph's big fall musicals, plus the school's drama club, glee club, and liturgical singers. She also studied voice and acting and was in the Prince Music Theater's Rainbow Company, which turned out a stream of Philly teens who went on to professional acting. In summers, she was with a youth performance group at the city's recreation centers.

"I saw it in her then - you could just tell she had that drive and she had that spark," says Joey DiMarco, at the time the head of Mount St. Joseph's music department and producer of its musicals, now a voice teacher in the theater department at DeSales University near Allentown. "So I'm not surprised at her success - but I am so proud."

When Hemingway got to Catholic University in Washington, she didn't do much on stage - ensemble roles, mostly. "I studied and worked hard," she says. After graduation in 2005, she headed to New York and auditions, continuing classes. "I concentrated on acting. I had no Equity [actors' union] card and no agent and I knew I wanted to perform - I just wasn't sure it was musical theater. I auditioned for straight plays. I was in that discovery phase."

Hemingway did, however, audition for Theatreworks USA, the touring children's theater company, and was hired in a cast of six for its Junie B. Jones musical. "We had two vans," she explains, "and one had all the sets, the other had all the cast. If we could get to a Super 8 or a Red Roof Inn, we would sleep overnight, then get up the next morning and set up all the scenery ourselves. It was a lot of fun." It also got her an Equity card, opening the doors to a new level of auditions.

And it renewed her original passion. "I remember saying to myself, 'Oh, I actually love this musical theater.' I re-embraced it. It's in me."

Hemingway signed with an agent during callbacks after her initial Mamma Mia! audition. She didn't know whether the auditions were for the Broadway cast - the show is still running - or the national tour, and when she got the touring role, she found herself at a new level. "It's a different world when you get to that point - Broadway national tours are produced with the same standards as the Broadway production. You're treated very well, your contract's very nice, you have a generous per diem."

For a year, she toured 40 cities, "learning what it means to do eight shows a week and play in big houses. It takes getting used to - knowing how to carry the momentum of a show. There's a lot of weight on you. I loved touring."

After her stint in Los Angeles in Parade, she was called to audition for How to Succeed - not the show itself, but a reading of the show. "I actually didn't think it went well, but they called my agent within a half-hour." She found herself reading with a cast that included Daniel Radcliffe. "We got along straight from the beginning," she says. "He's very easy to get along with - he's such a nice guy."

Then came the offer - not Hemingway's first for that show: When she was a high school freshman, the all-boy La Salle High recruited girls for its How to Succeed production. Hemingway took a role in the ensemble. She had nowhere to go but up.

Read The Inquirer's review of "How to Succeed in Business Without Really Trying" at http://
Contact staff writer Howard Shapiro at 215-854-5727 or Follow him on Twitter at #philastage.