SEX-abuse victim Fiona Doyle is to make an official complaint to gardai that her mother failed to protect her during years of abuse by her father.
Ms Doyle is taking legal advice about pursuing a case against Bridget O'Brien for failing to safeguard her when she lived at the family home in Dun Laoghaire.
She is planning to make an official complaint to gardai before the end of this month.
In evidence, she told Dublin Circuit Criminal Court that her mother was aware of the abuse and left her "at the mercy of my father, almost certainly knowing what he would do to me".
Patrick O'Brien was jailed last month after pleading guilty at the Central Criminal Court to 16 charges of rape and indecent assault of his daughter from 1973 to 1982.
Following public outrage, Judge Paul Carney reversed an earlier decision to release the 72-year-old on bail.
The Director of Public Prosecutions is appealing the leniency of the sentence, which was 12 years with nine suspended.
Ms Doyle's daughter Kristel O'Brien said her mother wants charges brought against her mother so those who tolerate abuse know they will be held accountable.
"Mum is looking into what she can do to bring my grandmother to justice, possibly on the grounds of child neglect," she told the Irish Independent.
"She is getting guidance on what can be done legally. My grandmother definitely knew about the abuse."
She said her mother was pleased that her father had not appealed his sentence by a deadline this week, and was very happy that the DPP was appealing the length of his sentence.
"I think it's brilliant," she said. "I think it's great that the system is saying the wrong thing was done and doing what it can to rectify it. It gives hope to other victims. It's given my mum hope. I don't think there is a suitable sentence for what he did, but what he did get was unsuitable."
Meanwhile, the Dublin Rape Crisis Centre welcomed the DPP's decision to appeal O'Brien's sentence.
Chief executive Ellen O'Malley-Dunlop said the 12-year term indicated the seriousness of the crimes committed, but having nine years suspended was "not an encouraging message".