Her father, Jason Richard Struhs, 53, and the leader of the family's religious group called "The Saints," Brendan Luke Stevens, 63, had been charged with the more serious crime of murder, but Queensland Supreme Court Justice Martin Burns found both guilty of manslaughter.
Burns also found another 12 members of the congregation, including the victim's mother, Kerrie Elizabeth Struhs, 49, and the victim's bother Zachary Alan Struhs, 22, guilty of manslaughter.
The victim's adult sister, Jayde Struhs, told reporters outside court that she welcomed the verdicts.