A Brisbane mother who was killed one year ago has been remembered by her family and friends as a high achiever, a model mum and an unselfish soul.

Allison Baden-Clay's body was found on a Brisbane creek bank on April 19, 2012, 10 days after she was reported missing from the family's Brookfield home.

Her husband Gerard Baden-Clay is on trial for murder.

Ms Baden-Clay's loved ones released a letter on Friday to mark one year since her death.

"Allison has been constantly in our thoughts," they said.

"Not for the circumstances and uncertain nature of her passing, but for the wonderful person she was.

"After 12 months, Allison is missed more than ever, and she is most surely not forgotten.

"She had done so much, yet had so much to live for and oh so much more to do."

The family and friends thanked the Brookfield community and the public for their love and support.

"We often cry because her life has come to an end but we also smile because we were privileged to have her in our lives," they said.

"A high achiever, a model mum and unselfish soul all of which were achieved under sometimes challenging circumstances, yet she rose above any adversity and endured many difficulties, yet she still loved.

"She will remain forever in our hearts."