"Tragedy + time = humour." After a lifetime of ups and downs Marie Osmond has put that hard-won revelation to work in her new book, "Might as Well Laugh About It Now."

"They wanted me to write an autobiography and I said I'm only half dead," Osmond, 49, told CTV's Canada AM in an interview from New York.

Co-authored by Marcia Wilkie, Osmond credits a devastating fire that consumed her home in 2005 for forcing her to pen this heartfelt, funny memoir.

"Thirty years of journals went up in flames," says Osmond, who ironically recalls assessing her home's resale potential after the fire. "Lots of natural light, great mountain view, great drive-thru kitchen," she writes. Yeah, people would be rushing to buy this celebrity-owned ash heap.

The incident left Osmond feeling twinges of pain after losing one-of-a-kind photos of her and brother, Donny, with Hollywood icons such as John Wayne, Groucho Marx and Lucille Ball.

What bothered Osmond more deeply, however, was what the loss of her journals would mean for her eight children.

"I did this book to have the memories for my kids," says the singer and actress who first hit the big time at 13.

Exploding onto the music charts with the song "Paper Roses," Osmond's performance marked the first time in country music history that a female artist debuted with a number one record.

Earning Grammy nominations in 1974 for Best Female Country Vocal Performer and Best New Artist, Osmond's fame exploded in 1976 with the launch of "The Donny & Marie Show."

Airing from 1976 to 1981, the weekly television variety series turned the two Osmonds with the big, picket-fence smiles into international superstars.

Osmond's fame didn't come cheap

Osmond chronicles the price and impact of her celebrity with breezy candour.

From the difficulty of finding herself after "The Donny & Marie Show" ended to two failed marriages, the loss of her parents, battles with bulimia, and her much publicized weight gain and loss of 46 pounds, the NutriSystem spokesperson bares it all.

As Osmond writes:

"Being in show business, the pressure to always look good had sadly been ingrained in me so deeply by age 10 that even an earthquake couldn't shake that concern from my head...I know now that some of my weight issues were in reaction to difficult issues of my childhood... I dreaded being on the cover of Tiger Beat magazine along with my brothers...I felt flawed in this family of what seemed like perfect boys."

Using her closet as her childhood confessional, Osmond retreated into its furthermost corners and sobbed frequently about all her insecurities.

"I wished I could disappear," she writes. "I wanted to start over again, to be born beautiful like Donny. Little did I know that it was only the beginning of 30 years of complicated issues regarding my body image."

The Vegas performer and 2007 "Dancing with the Stars" contestant also uses her new book to set the record straight about her father - the patriarch of one of the most successful entertainment families in showbiz history.

"My dad was always portrayed as being a stern parent, almost maniacal. As his daughter I had to set the record straight," says Osmond.

"He was a good man. It's hard to fine them these days...My mom was the insane one...She was so funny," says Osmond, who told CNN's Larry King last week that her next project will be a talk show from Las Vegas.

Turning 50 in October of 2009, Osmond hopes her milestones, mishaps and insights on everything from ear piercing to death will help audiences, particularly today's youth.

As Osmond says, "It's good to wait for certain things. Children want tattoos now but I say what till your responsible and old enough to really make those big decisions in your life. I have two tattoos," she says with a laugh. You'll have to read where they are."