Justin Bieber's Mom

"My mom is the strongest woman I've ever met," writes Justin Bieber, Mallette's son. "I've always known it, but this book has helped to remind me just how strong she is."

Lest we doubt his objectivity, Nowhere But Up -- helpfully subtitled The Story of Justin Bieber's Mom -- details Mallette's struggles and sacrifices, from a youth marked by sexual and drug abuse and feelings of abandonment to teen pregnancy and single motherhood.

"I've spent most of my adult life sifting through the tangled web of emotional wounds and the debris left by the darkness in my childhood," Mallette writes in Chapter One. We learn of the tragedy that devastated Mallette's family months before she was born; of the trail of molesters who made her believe she was "just a dirty girl," from a male babysitter to a friend's grandfather.

Nowhere But Up also chronicles Mallette's tumultuous relationship with Bieber's father, and the spiritual awakening she had when she was visited by a Christian counselor in a psychiatric ward, after a suicide attempt. (The book was co-written by A.J. Gregory, whose own titles include Messy Faith: Daring To Live By Grace and Silent Savior: Daring to Believe He's Still There.)

"I always wanted to write a book about my story," Mallette, 36, says in an interview. "I wanted to be as vulnerable as I could, so that young girls who have been through similar things could relate. I pretty much bared my soul. It definitely furthered my healing process."

Mallette uses that last term repeatedly inconversation. She calls Nowhere But Up part of her "healing journey," in which "faith has played a huge role. I'm really grateful to God and to all the people who have surrounded me and loved me."

She took others' sensitivities into account while writing Nowhere But Up, she says. "In sharing difficult moments, I wanted to find that fine line between truth and honor. I didn't want to blame anybody or shame anybody; we're all imperfect and we all make mistakes."

The book is at its sunniest when the focus is on Mallette's famous son, whom she describes as having been a precocious, energetic little boy whose musical gifts were rivaled only by his love of and affinity for sports.

Asked if she was wary of letting Bieber pursue a career in show business, given her own experience with unsavory characters who preyed on her guilelessness, Mallette says: "Absolutely. You hear all the horror stories about kids and teenagers in this industry, and I didn't want to throw my son to the wolves. I've done my best to protect him and surround him with good people."

Mallette allows that she can't watch Bieber's every move as closely as she used to. "He's 18 now and wants to be independent. But I still travel with him when I can. It's a bit of a whirlwind, but we've always been pretty flexible and spontaneous about it."

She adds that Bieber -- who just released a new book, Just Getting Started -- a follow-up to 2010's First Step 2 Forever: My Story -- has been a consistent cheerleader for her new project:

"He's really supportive, and really proud of me."