Catherine Nevin has lost an attempt to have evidence of her conviction for the murder of her husband Tom excluded from a civil case aimed at stopping her from inheriting his estate.
Mr Nevin's brother and sister have taken a High Court action to disinherit her.
They claimed her conviction should be used as evidence in their action.
High Court President Mr Justice Nicholas Kearns today said to rule out the conviction as completely inadmissible would "be contrary to logic and common sense and offend any reasonable person's sense of justice and fairness".
However, the judge said Nevin's conviction could be used as "prima facie evidence only" and it was still open to her to contend in the civil proceedings that she was innocent.
The 61-year-old was jailed for life after she was convicted almost 13 years ago for the murder of Tom Nevin at Jack White’s pub in Wicklow in 1996.
Mr Justice Kearns also called for an amendment to the 1965 Succession Act to address an anomaly identified during the case.
Sections of the act dealing with exclusion of persons from succession differed in the use of the phrase "guilty of" for murder and "found guilty" of lesser crimes.
According to the judge, this was "an extraordinary omission for which it was difficult to find any rational explanation". The anomaly meant the plaintiffs in the case could not rely on the act.
Because of the wording it could only be a declaration of public policy that the perpetrator of a crime of murder should not be its beneficiary.
The judge also dismissed Nevin's argument that the civil case should not go ahead until all criminal proceedings were completed.
A considerable amount of time had elapsed since her conviction due to her fully exercising her rights under the criminal law system.
Nevin's appeal against her conviction was dismissed in 2003.
She later lost an application to have it declared a miscarriage of justice, but is currently seeking to have her case heard by the Supreme Court.
Tom Nevin did not leave a will. His assets included Jack White's pub, which was jointly owned and sold by his widow in 1997 for £620,000.
His estate also included two Dublin properties, a life assurance policy and cash.