June 8, 2012 — -- Dominique Moceanu was the youngest member of the celebrated "Magnificent 7" gymnasts who won team gold at the 1996 Olympic Games. But behind the broad smile and shining medals she hid heartache and pain inflicted by some of the people she trusted the most.
Her parents, Dimitry and Camelia Moceanu, came to the United States from Romania in the early 1980s to escape the brutal regime of Nicolae Ceausescu. Both had been athletes and had high hopes for their first child.
"My dad, he wanted a better life," Dominique Moceanu said in an exclusive interview with "20/20." "I think he wanted me to do something that he didn't get a chance to do."
They enrolled 3-year-old Dominique in gymnastics and soon it became clear that their daughter had a special gift. "Gymnastics was my calling. I think it chose me in a lot of ways," she said.
Setting their sights on the 1996 Atlanta Olympics, Dominique Moceanu's parents took her to try out for the famous Olympic gymnastics coaches Bela and Marta Karolyi when she was 9. To the Moceanus' delight, she was accepted into their rigorous program, and the family moved to Houston, Texas, to pursue her training.
"Bela Karolyi is the greatest kingmaker we have seen in gymnastics," said Christine Brennan, ABC News contributor and sports columnist for USA Today. "And Dominique Moceanu had to have Bela Karolyi to become the gymnast that she was to become."
At just 13-years-old, Dominique won the 1995 U.S. National Championships, beating out much more seasoned and experienced gymnasts. Her place on the Olympic team seemed assured and even a stress fracture in her leg right before the games didn't stop a determined Moceanu from competing.
She breezed through the first three routines -- uneven bars, beam and a floor routine during which she performed to "The Devil Went Down to Georgia" before an adoring Atlanta crowd. But it would be during her final event -- the vault -- when, she said, her world caved in.
"I was shocked," Moceanu recalled, remembering how she felt after falling on both landings. "I couldn't believe that I would sit both of my vaults down when it came to it."
In the end the U.S. team won gold, but Moceanu still feared the reaction of her father, who would chastise her after the medal ceremony. "I have this gold medal around my neck. I wanted to take it off. I was devastated. It was heartbreaking."
Moceanu would ultimately file for emancipation from her parents when she was 17,and got a restraining order against her father. After an injury quashed her bid for the 2000 Olympics, she went to college and was married in 2006 to a fellow gymnast named Mike Canales. Two years later, Moceanu's father, Dimitry Moceanu, died after a long battle with cancer.
While Moceanu grappled with her father's illness and looming death, she also underwent another life-changing experience: becoming a mother. She became pregnant with her first child soon after her marriage to Canales.
But two weeks before giving birth, Moceanu learned some shocking news. She received a package containing a letter and photos of a young woman who looked surprisingly similar to her younger sister Christina.
Reading the letter, she learned that the 20-year-old woman, named Jen Bricker, had been adopted and had recently learned that her birth name was Moceanu.
"It was the biggest bombshell of my life," Dominique Moceanu remembered. "I had this sister that was born who was given up for adoption, and I never knew it."
Moceanu confronted her mother and ailing father, who told her that the baby had been born the day after her sixth birthday. They had been poor and doctors had told them the child would require expensive medical care, so they gave her up for adoption. When Moceanu reached out to her new sister, Bricker confirmed the unusual condition that led doctors to recommend expensive care.
"Oh by the way. I have no legs," she told a stunned Moceanu. "But people forget that within minutes of meeting me."
Five years later, they have met many times and have developed a friendship and bond that only sisters could have. They're athletic, do gymnastics -- Bricker even competed in the Junior Olympics -- and have discovered other striking similarities.
"The tones in our voices, our handwriting, the way we laugh and chuckle. It's mind-blowing," Moceanu said.