Teresa Reichlen in George Balanchine's "The Four Temperaments." (Paul Kolnik/New York City Ballet)

That body. Those legs. She was just 10, but Teresa Reichlen made an impression on her new ballet teacher before she’d even danced a step.

“I’m walking around assessing my new young students, and I walked by her and did a double take,” said Margaret Virkus, recalling the day Reichlen, now one of New York City Ballet’s most prized ballerinas, showed up in her class. It wasn’t often that a child holding so many aces walked into the storefront studios of the Russell School of Ballet, tucked away in an office park in Chantilly.

“She had the perfect physique: long, lanky, straight legs with a lot of rotation in the hips. Beautifully arched feet,” Virkus said. “And I was like, ‘What’s your name, little girl?’ ”

Reichlen gave her nickname, Tess, barely above a whisper. She was shy; the school’s founder, Thomas Russell, remembers that for years he had to nag her to look up, rather than down at the floor. But coiled inside that quiet slip of a girl was a hunger for challenge that fueled her rapid mastery of the trickiest aspects of ballet technique. Once the Clifton native hit her teens, Reichlen’s teachers discovered she could perfect any turn and nail any balance they asked of her.

That granite technique powered Reichlen’s rise from Centreville High School through the New York City Ballet ranks, starting as an apprentice at 16 and becoming a corps de ballet member a year later. At 27, she is a singularly versatile principal dancer, recognizable for her height — at just under 5-foot-10, she’s Amazonian by ballerina standards — and her Ivory Soap-girl wholesomeness. She could be your sister or the volleyball coach.

New York City Ballet’s principal dancer Teresa Reichien. (James Patrick Cooper)

It all seemed to come so easily to her — the athlete’s speed, the voracious jump, that confidence mixed with a little sass. Reichlen conquered one devilish role after the other; she’s especially known as the high-kicking, alpha-Rockette soloist in the “Rubies” section of Balanchine’s “Jewels,” and for her dominatrix Siren in “Prodigal Son.” She gained a reputation as a Balanchine ballerina for a new age, neither seductive nor aloof but fresh and uncomplicated.

Then, a few years ago, Reichlen hit a wall. Her “obsession” with technique, as Reichlen calls it, almost choked the life out of her dancing.

“I was really close to stopping ballet,” Reichlen said.

She spoke recently via Skype from Amsterdam. Wearing her long blond hair loose, her face a pale oval but for the bright blue of her eyes, Reichlen could have been any college kid — which is exactly who she is in the rare moments when she’s not dancing. Taking one or two courses a semester, she is working toward a biology degree from Barnard College.

Reichlen was in the Netherlands with her boyfriend, New York City Ballet dancer Justin Peck, to rehearse a duet Peck had choreographed for her and a member of the Dutch National Ballet. After that, she was headed to St. Petersburg to squeeze in a performance of “Prodigal Son” with the Mariinsky Ballet Company, just before traveling here for the New York City Ballet’s series at the Kennedy Center Opera House, Tuesday through April 8.

Reichlen has featured roles in two works on the company’s “All American” program. On alternating nights, she’ll dance in Balanchine’s jazzy “Who Cares?” with its Gershwin score, and in the sharp, angular “Fearful Symmetries,” choreographed by Ballet Master in Chief Peter Martins, with music by John Adams. (Also on the bill is Jerome Robbins’s “West Side Story Suite.”)

She’s not only a chief attraction, she’s the embodiment of the program’s theme. Reichlen is ballet’s girl next door. With her sidelong glances and unaffected glamour, she’s a Peggy Lee in pointe shoes.

Reichlen grew up with three brothers, and credits them for her air of tolerant toughness. She seems so unflappable onstage it’s difficult to imagine she ever struggled with a lack of confidence. But she describes the time about three years ago when she lost her way in the company’s highly competitive atmosphere.

“I wasn’t performing very often, and when I did I was putting so much pressure on those few shows that if they didn’t go well or if someone said, ‘Oh, you could do more,’ I would overanalyze it. I was too much in my head.”

She was a soloist, and to move up in rank, Reichlen drilled down on mechanics. That always had been her strength. Surely, faster turns and crisper steps were the answer!

“But I was focusing on the wrong things,” Reichlen said. “I was not really concerned with port de bras” — the shape and movement of the arms — “or presentation, but with how turned out I was, how well my pirouettes went, where my feet were placed. I probably gave incredibly boring shows. Who wants to just see technique?”

Her coaches were unimpressed. “Can you do more?” they’d ask.

“I don’t know if I really understood what that meant until the last few years,” Reichlen said.

The subtleties of dancing — the flickers and ripples of enchantment, the perfume of a performance — are far more difficult to teach than the steps. Martins, speaking by phone, says a coach walks a fine line between imposing a style and letting the dancer discover her own expressiveness.

“From the waist down is impersonal,” Martins said. “From the waist up is personal.” Legs and feet have to move in pretty much the same way from dancer to dancer. But the arms, head and neck — how they respond is a more individual matter.

Over time Reichlen figured it out. “I’ve really embraced trying to go out onstage and have a good time and tell a story,” she said. “To evoke some sort of emotion from the audience, and to really let the music kind of infect my body.”

Her promotion to principal came in 2009. She met another goal last fall, when she danced the leading role in Martins’s “Swan Lake.” The chance to act enthralled her.

“It was a lifetime dream,” she said. “And how many people’s specific dreams come true?”

“It was obvious that she should do ‘Swan Lake,’ ” Martins said. “Because of her look, her unbelievable line and technique — it was just a waiting game.”

“Her greatest strength at this point is that she’s not typecast,” he continued. “There is an unbelievable range of roles she can fit. She can be beautifully lyrical in ‘Concerto Barocco,’ she can do the Dark Angel in ‘Serenade,’ she’s fantastic in ‘Fearful Symmetries.’ ”

One of Reichlen’s few problems now is finding a partner who is tall enough. Charles Askegard was a frequent match, but he retired last fall.

Martins said he is “always looking out for my tall ladies,” and Reichlen need not worry.

“She has a big future in front of her without a doubt.”

Gone are any thoughts of quitting. “I hope to expand my Robbins repertoire, dance more of the great Balanchine ballets,” Reichlen said. “I kind of want to do everything.”

And having reflected on her past with solemn matter-of-factness, the perfectionist who’s no longer at war with herself breaks into a satisfied smile. “I feel like I’m just entering my prime now.”

New York City Ballet

performing two mixed-repertory programs Tuesday through April 8 at the Kennedy Center Opera House. Program A, “All American,” features works by Balanchine, Robbins and Martins. Program B, “21st Century,” features works by Ratmansky, Wheeldon and Martins. $25-$85. kennedy-center.org .