''This is an issue that the Supreme Court is going to hear at some time in the future," said Jordan Lorence, one of Britain's lawyers. Lorence works for a conservative Alliance Defense Fund.
Carvin and Britain had lived together for five years before they decided to become parents.
Britain was inseminated, and then gave birth in 1995 to the daughter, known as L.B. in court papers. The girl called Carvin ''Mama" and Britain ''Mommy."
Britain broke up with Carvin in 2001, and the following year, when the girl was 7, she barred her former partner from seeing the girl. After Carvin went to court, Britain married the sperm donor. They now live in Thailand. Britain and the child are with the donor for an extended visit, lawyers said.
Eighteen states recognize ''de facto parents" over objections of fit biological parents, Britain's lawyers said. They are Arizona, Arkansas, California, Colorado, Indiana, Kentucky, Maine, Maryland, Massachusetts, Minnesota, New Jersey, New Mexico, Pennsylvania, Rhode Island, Utah, West Virginia, Washington, and Wisconsin.
The case appears to paint a difficult battle between the two women. Britain said that she wanted to have the girl baptized in a Roman Catholic church, and that her former partner wanted to take L.B. to a Buddhist temple. Carvin said she was the active parent, while Britain focused on her job.
Carvin and her lawyers said they were pleased that the justices did not disturb a Washington state court ruling in the fall.
That ruling asserted that though Carvin was not the girl's natural or adoptive mother, she may have been a ''de facto parent."
''Symbolically, it is definitely an important decision, acknowledging that families are changing," said Nancy Sapiro, a senior lawyer attorney with the Northwest Women's Law Center, and a Carvin lawyer. Carvin said in a statement that she was ''thrilled that the United States Supreme Court decided not to review this case and that the Washington State Supreme Court decision will stand." Nancy Polikoff, who teaches family law at American University, said: ''As lesbian and gay couples more frequently raise children together, breakups of those families are more likely to happen and there will be more disputes. Courts will have to deal with it."
Kristen Waggoner of Seattle, one of the lawyers for Britain, said the two sides have reached an agreement that could be final in a few weeks.
