Siobhan Vivian writes about intelligent girls, friendship and finding oneself. She also talks about messing up and deception, the kind that tears apart her characters' worlds.

Although they piece their lives back together, their experiences change them in crucial ways. That's what makes Ms. Vivian's work so compelling and her stories so real.

You wait for revelations; you dread the wreck ahead. The results are unpredictable but satisfying and full of hope.

Ms. Vivian, a recent transplant to Pittsburgh, has made herself at home in our city. A graduate of New York's New School with a master of fine arts in writing for children, Ms. Vivian teaches at the University of Pittsburgh. She's even incorporated Pittsburgh into one of her stories.

In her 2008 debut novel, "A Little Friendly Advice," (Scholastic Push) Ruby's adorable boyfriend, Charlie, had lived in Pittsburgh once. His father taught art at Carnegie Mellon and Charlie often comments on what a great city it is.

Charlie helps Ruby cope with the changes around her when she finds out her mother and her closest friend weren't honest about her parents' break-up years earlier.

A secret romance and hidden friendships collide in "Same Difference" (Scholastic Push, 2009), another of Ms. Vivian's books, this time set at the other end of the state.

Emily has always lived in the suburbs. Her world opens up when she encounters an unpredictable artist at an art program in Philadelphia. She reinvents herself and at the same time pushes away Meg, the friend who's always been there for her.

Ms. Vivian's latest heroine, Natalie, lies to herself and strains a promising relationship so she can believe she's "Not That Kind of Girl" (Scholastic, $16.99, ages 13 up).

Unlike Spenser, a younger girl that Natalie used to baby-sit, Natalie would rather triumph with good grades and ambition than sex appeal.

She especially wants to please her favorite teacher, Ms. Bee. She was one of the few female student council presidents in the school's history, and she puts pressure on Natalie to excel.

So Natalie runs for student council president of Ross Academy with the aid of Autumn, the best friend who will do anything for her. Natalie narrowly defeats football player Mike Domski, who enters the contest as a joke.

She sets about making student government into a well-oiled machine. But things don't go the way she plans.

Natalie finds out that Connor, the boy every girl wants to have, may be interested in her. He slips his phone number to her at a dance. That begins a streak of late night hook-ups in an out-of-the way shed on his family's Christmas tree farm. She insists they keep their relationship secret.

Meanwhile Natalie alienates her former friend, Autumn. She's fed up with Natalie for not wanting to socialize and for judging others. She questions whether their friendship had ever been good for her.

One of this novel's great strengths is how conflicted we know Natalie feels. She's so terrified of being hurt and desperate to maintain control. At the same time that she finds it nearly impossible to be on her game while she's sneaking out at night to be with Connor. She can be curt, which hurts the people who care about her most.

Despite Natalie's negative impulses and behavior, she remains an understandable and likable character. Flaws and all, Natalie is someone we can relate to.

It turns out Connor is much kinder and more liberated than Natalie ever expected a boy to be. Their interludes in the shed, full of warm bodies and hotly contested conversations, ring true for teens at the very start of their romantic lives. Ms. Vivian writes convincingly of those first stirrings of sexuality -- awkward, passionate and full of yearning

Like Natalie, Connor is a complex character. He's a smart boy who plans to take over his family's business instead of going away to college.

He's a man's man, the quarterback of the school's team, but his four older sisters and a mom he admires makes him sensitive to women. In some ways, his loyalty to Natalie and Mike, who often acts like a jerk, is almost too good to be true. Although he doesn't agree to meeting in secret without protest, that doesn't stop him from pursuing her.

When Natalie finally realizes how much she cares about him, her actions make her feel strong and independent, the opposite of what she feared.

But Natalie worries about having a good reputation. She's incensed that boys get away with things and girls get the fallout. And she's too self-absorbed to realize how badly she treats Connor.

Ms. Vivian is masterful at pulling away Natalie's layers of self-deception, one by one. Natalie thinks in terms of "a girl like that" or "a boy like Connor" and worries about being judged. She doesn't realize, until it's almost too late, that although others may judge her, what matters most is how she feels about herself.

Like Ms. Vivian's other novels, "Not That Kind of Girl" is a joy to read. It's full of wry observations, details that delight the senses and perceptions about the things that matter.

She treads a delicate path that explores first love, hard-won independence and all the obstacles that make growing up such an intense challenge and triumph. Any girl, or anyone who cares about girls, will enjoy this book's riches.

Looking for more from the Post-Gazette? Join PG+, our members-only web site. You'll get exclusive sports content, opinion, financial information, discounts from retailers and restaurants, and more. Our introduction to PG+ gives you all the details.