In the '90s, Mary Kay Letourneau made headlines for her inappropriate sexual relationship with a 13-year-old student. On Friday's 20/20 special, we'll meet her two teenage daughters whom she had with her former preteen victim, Vili Fualaau, now her husband.

The couple got married 10 years ago, after Letourneau served seven years in prison for two counts of second-degree child rape. Letourneau gave birth to Audrey, now 17, while out on bail from her first arrest, and had daughter Georgia, 16, while serving time behind bars.

Watch the first promo for Bruce Jenner's 20/20 interview

In 1996, Le Tourneau was teaching sixth grade in Washington state. Four years earlier, Vili Fualaau had been in her second-grade class at Shorewood Elementary School; once again, he was her student. When Letourneau was 34 and Fualaau was 13, she entered into a sexual relationship with him. Though Fualaau would later claim the relationship was consensual, it was statutory rape.

After giving birth to their first child, Letourneau served six months in prison. She had been sentenced to 89 months, but had the rest of her sentence suspended on the condition that she not contact Fualaau.

Two weeks after she got out, she was found having sex with Fualaau in her car. He impregnated her again before she was sentenced to seven and a half years in prison.

After she was released, she and Fualaau got married in a televised ceremony. They also co-authored a book, titled "Only One Crime, Love."

As a child, Letourneau watched her parents' marriage crumble after the family discovered her father had had two children out of wedlock with a former student at Santa Ana College, where he taught political science. The revelation also ended his career in politics — he had served as a Republican congressional representative and was planning to run for the U.S. Senate at the time.

On Friday, Barbara Walters will interview the family on a special episode of 20/20. Letourneau, now 53, says her daughters are aware of the circumstances under which they came into the world. Georgia and Audrey Fualaau attended the same school district where their mother taught and subsequently victimized their father.

The special 20/20 interview airs Friday at 10/9c on ABC.

TODAY'S VIDEO: The 17 best animal moments from The Amazing Race