Newswise — Katherine Schwarzenegger felt something was obviously and terribly amiss one day last summer, when she overheard her young cousins chatting with each other about their bodies.

“They’re 8 years old and were talking about how they don’t want to be fat, and how they want to be ‘sexy,’” she said. It wasn’t the first time Katherine had heard the girls and her other young friends divulge body image issues.

The 20-year-old daughter of famous parents, Gov. Arnold Schwarzenegger and Maria Shriver, Katherine is familiar with the struggle to maintain self-esteem. As a teen, her own battle to appreciate her self-worth was magnified under the scrutiny of the public eye.

In time, Katherine, now a junior Communication major at the USC Annenberg School for Communication & Journalism, tackled her body image issues and earned self-confidence. To encourage other young girls – and their mothers – she began writing about her struggle. Sept. 14 will mark the release of her first book, “Rock What You’ve Got: Secrets to Loving Your Inner and Outer Beauty.”

The book came out of her drive to counsel not just her own young cousins but other girls struggling with self-doubts and anxiety about their bodies. She wanted to speak to a wider audience.

“I want girls to read this and feel that it’s OK to be themselves – and to understand that every girl can be beautiful no matter what size and shape she is,” she said.

“You don’t have to look like you’re on a billboard to feel beautiful. I really wanted to correct girls’ perception of that.”

In “Rock What You’ve Got,” Katherine tells her own story of growing up as the daughter of both a famous bodybuilder-turned-blockbuster celebrity and a mother who also built a successful career in front of the camera. Katherine’s mother faced her own pressures growing up under the strict food rules of mom Eunice Kennedy Shriver, who was 5’9” and never weighed more than 100 pounds during most of her adult life.

As a result, “Mom never forced us to eat or stop eating,” Katherine writes. “She never policed us.”

Her father, on the other hand, was much more of a food watchdog and more prone to ask, “Are you sure you need that second helping?” and point out how many calories were in the muffin she was eating. And it was no fun for the kids in the house when he was gearing up to film a movie and would tear through the house, trashing all the ice cream and junk food.

Katherine pulls back the curtain on the Kennedys as well – or at least how she felt growing up as a Kennedy. In keeping with the heart-to-heart tone of the book, Katherine reveals how she felt like a misfit during summers at her family’s compound on Cape Cod. The hairstyle, multiple earrings and dark nail polish she wore to express herself in LA made her feel “a little like the black sheep in my conservative extended family,” she writes. The questions and criticism from her cousins made her feel “insecure and lost.”

But she credits her parents with the strict but supportive upbringing that made her feel secure and ultimately steered her toward mature decisions. Her mother, she says, was not one of the “cool” moms; she was reassuring and never judgmental, but she but wasn’t a pushover. There was no negotiating.

“I think that throughout the book, you get a sense of how real they really are and how they’re really like every other parent,” Katherine said. “They deal with the exact same issues every other parent deals with.”

Also throughout the book, Katherine weaves in interviews with experts, research (much of it from the Dove Campaign for Real Beauty, which she worked for as an intern) and statistics on eating disorders, body image issues, plastic surgery, birth control and other topics. Her “moms only” sections give advice to moms aiming to raise healthy teen and pre-teen girls.

Her own open relationship with her mother also motivated her to write the book, Katherine said. She encourages readers to strengthen their ties and seek advice from their own mothers as they struggle with self-doubts.

It was also a class at Annenberg two years ago that drove Katherine to explore writing a book, she said. Communication Professor Alison Trope’s course on the effects of media made an impression on her. She wanted to learn more.

Katherine is set to graduate in the spring of 2012 and hasn’t yet settled on a career track. For the moment, she is enjoying pursuing her passions. She also is the creator of a project called VIDA bags, which raises money to fight maternal mortality.

“I never thought I would write a book,” she said. “But my fuel came from research and information on the growing number of girls who feel so much pressure to be thin – and how young all of this is starting. My goal is to let girls know they’re not alone when they’re going through this and to spread the word about what young girls are going through today.

“Society needs to know about the kind of pressure that is put on girls. We have to change it in some way.”

Katherine’s promotional tour over the next few weeks includes: stops in New York City, Washington D.C., Austin and Miami – and appearances on Good Morning America, The View, the Rachael Ray Show, @katiecouric, The Gayle King Show, Extra, Good Day LA, Access Hollywood Live, Entertainment Tonight and Inside Edition. She works it all into her class schedule at USC Annenberg.

About the USC Annenberg School for Communication & Journalism

Located in Los Angeles at the University of Southern California, the Annenberg School for Communication & Journalism (Annenberg.usc.edu) is a national leader in education and scholarship in the fields of communication, journalism, public diplomacy and public relations. With an enrollment of more than 2,200 students, USC Annenberg offers doctoral, graduate and undergraduate degree programs, as well as continuing development programs for working professionals, across a broad scope of academic inquiry. The school’s comprehensive curriculum emphasizes the core skills of leadership, innovation, service and entrepreneurship and draws upon the resources of a networked university located in the media capital of the world.