The daughter of Celine Cawley and Eamon Lillis is taking a legal action against her father.
Ms Cawley was killed by her husband, Eamon Lillis at their home in Howth in December 2008.
He was convicted of manslaughter last year and is currently serving his sentence of six years and 11 months.
Ms Cawley's brother, Chris and sister, Susanna began legal proceedings against him to disentitle him of any share in the assets he and Celine Cawley owned together.
They argued that all the assets should go directly to the couple's daughter, Georgia Lillis.
Ms Lillis turned 18 last year.
The court was told she now wants to become involved in the legal proceedings against her father and the court was asked to make an order joining her as a co-plaintiff.
Ms Justice Mary Laffoy granted the order. She said Ms Lillis was the only other person, apart from Mr Lillis who would be affected by the outcome of the legal proceedings.
The court heard that Georgia Lillis wanted to be made a plaintiff in the case and felt 'exceptionally strongly' that she wanted to address matters that her father had raised in documents submitted to the court previously.
The court was told that Mr Lillis had made certain allegations about agreements between him and his daughter. The court heard she wanted to deal with them very firmly.
The application for Ms Lillis to be joined as a plaintiff was opposed by lawyers for her father. The court was told there was no necessity for Georgia to become involved as what had to be decided was a legal issue.
The court was told that the matter was very difficult for all the parties concerned.
And that Mr Lillis had concerns that the proceedings would be presented as 'father sues daughter'.
The court was told by lawyers for Mr Lillis that he still has a relationship with his daughter and continues to support her to an extent and did not believe it would be helpful for her to be joined as a co-plaintiff.