The bodies of Madeleine and Lauren O'Neill were found in their home
A mother who killed her child and then took her own life had given her 9-year- old daughter a sleeping tablet before smothering her, an inquest has heard.
Madeline O'Neill and her daughter Lauren were found dead in their home at Manse Road in Carryduff in July 2005.
Mrs O'Neill, who hanged herself, had been treated for psychiatric problems in the weeks leading up to the deaths.
The 41-year-old had also told health professionals that she thought about killing herself and her daughter.
Her estranged husband, John, gave evidence to the inquest that his wife had been abused as a child and had taken a case resulting in a successful prosecution.
He said that she had been haunted by what happened to her, and their relationship had deteriorated.
Mr O'Neill said that he had no idea she had told doctors she might harm Lauren, the first he had known was months after they died, when police told him they had found it in Madeline's medical notes.
He said he felt aggrieved that so many people in the health service had known about the threat to his daughter's life but none of them had acted or told him so that he could protect her and that no-one had been held accountable.
The case caused controversy after it emerged that there had been an apparent failure to transfer notes between the doctors who treated Mrs O'Neill at Knockbracken Health Care Park in south Belfast and staff at Gransha hospital in Londonderry where she had been transferred for further treatment.
Mrs O'Neill, was originally from Derry, had a history of depression and left hospital nearly two weeks before she died.
A 2008 report on the deaths found that the Western and Eastern Health Boards had failed to follow basic procedures.
The Department of Health has also commissioned an independent review of the case.
The Health Minister Michael McGimpsey has said he will await the outcome of the inquest before deciding whether to hold a public inquiry.