Deirdre Morley, who killed her three children while suffering from depression and psychosis, has issued a medical negligence action in the High Court against the HSE, St Patrick's Hospital in Dublin and a consultant psychiatrist over her care.
Her husband, Andrew McGinley, has filed a separate action against the same defendants.
The papers were lodged yesterday.
Ms Morley was found not guilty by reason of insanity last year of murdering her three children, nine-year-old Conor, seven-year-old Darragh and three-year-old Carla at their home on 24 January 2020.
After the killings, she was diagnosed with a severe psychotic depressive illness. She believed her children had been irreparably damaged by her illness and her parenting.
In hospital afterwards, she was prescribed anti-psychotic medication which she described as a "wonder drug". She said she wished she had been on it the previous week.
The trial heard evidence that she had first told psychiatrists she was concerned her mental health issues would affect her children in late 2018 and continued to express such thoughts during the following year.
The court heard she had masked her symptoms from her husband and others who were close to her to the extent that they did not know how seriously ill she was.
Mr McGinley had called for a full investigation into his wife’s diagnosis, treatment and medication before the tragedy. He has also been campaigning for family members to be allowed to be involved in the treatment of a loved one's mental illness.
Saturday will mark the second anniversary of the deaths of the three children.