Mrs Riggs went to Griffith Primary, Telopea Park School and Narrabundah College.

She was just 17 when she married Edmund Ian Riggs, who on Wednesday was charged with her murder after skeletal remains were found in the family backyard in Queensland.

Much of Mrs Riggs' married life was spent in Canberra. She worked as a swimming instructor and was involved with the local home birth association. She and her husband had four children.

She was living in Canberra as late as January 2001 when she worked at the Olympic pool.

The family moved to Brisbane in August of 2001.

Mrs Riggs was last seen at her home in Margate in the early evening of September 30, 2001 and reported missing to police three days later, on October 3. Police were told then she had walked out of her Brisbane home after an argument with her husband.

She was only 34.

Her mother Carol Saxton died in 2011, too late to finally have confirmation of what had happened to her beloved daughter.

But Mrs Saxon told The Canberra Times in 2003 she had no doubt Trish would never have walked out on her four children. It's understood she had been told as far back as 14 years ago that there was evidence of foul play in the house but police could do nothing without a body.

"I have no hope that she will turn up," Mrs Saxton told The Canberra Times in 2003. "Really, what I want is for the body to be found so that we can give her a dignified farewell."

Mrs Riggs' friend Lynn Nerdal said a memorial service was held for her in Queanbeyan in 2002.

Ms Nerdal has also maintained a Facebook memorial page for her friend. She said she hoped justice could finally be done.

"She was an amazing woman," she said. "She was a dedicated and devoted mother."

Mrs Riggs home-schooled her four children - Matilda, Harriet, Edgar and Macarthur. It's understood Harriet has since become a mother herself.

Tragically, it's understood the children grew up believing their mother had abandoned them.

But those who knew Mrs Riggs, believed that could never be the case.

Another friend, Kym Bryce, said on Facebook: "I was a helper at the births of 2 of Trish's children, in Canberra. Wonderful person, mother, friend. A sad loss to humanity."

Ali Sewter wrote: "RIP Tricia, you were a beautiful mother and incredibly devoted to your babes. I hope they know how much you loved them".

Linda de Smet said: "Trish was a beautiful spirited friend to me and my two daughters when she lived in Narrabundah ACT."

Mrs Riggs also wrote a book about birthing and was a volunteer at the Sydney 2000 Olympics in the aquatic centre.