A gay Irishwoman has taken legal action against her English former partner in a bid stay in touch with the partner's child.
Her former partner had given birth when the two women were living together in Ireland.
But they later separated and the Englishwoman moved to England with the little girl.
The Irishwoman has now launched legal action in family courts in Ireland and England in an attempt to stay in the little girl's life.
Detail of the case has emerged in a published ruling on the latest round of the litigation by an English High Court judge.
The Irishwoman wanted Mr Justice Holman to order her former partner to return the girl to Ireland.
Mr Justice Holman, who analysed issues at a hearing in the Family Division of the High Court in London in April, said judges in Ireland should have control and make decisions.
"The facts and circumstances of the case are a little unusual," said Mr Justice Holman.
"These two people were in a relationship, they moved forwards towards the conception of a child."
The judge added: "It is quite clear that in the period leading up to the birth of the child, both these people were viewing the prospective child as a joint child to be parented by them both jointly.
"In the months following the birth the applicant, as well as the mother, were both very actively involved in the parenting of the child."
The judge has not identified anyone involved or said where exactly they lived.