The state Supreme Court let stand a lower court decision giving a non-biological, lesbian mother primary custody of the children she helped raise with their biological mother.

Generally, courts favor a biological parent in custody disputes. But in this case, the Pennsylvania Superior Court upheld a ruling by a Bucks County judge who had found it was in the two children's best interest to stay with their non-biological mother because she was more stable and capable of complying with the custody agreement order.

It was not necessary to find the natural mother "unfit" as a parent, Judge Susan Devlin Scott had said. The non-biological other mother only had to show "clear and convincing evidence" that it was in the children's best interests to reside with her.

The couple, Ellen Boring and Patricia Jones, began living together in 1988. Ms. Boring was artificially inseminated, with sperm from an anonymous donor, and gave birth to twin boys in December 1996. The women raised the boys together until they split in January 2001.

During their relationship, the non-biological mother, Ms. Jones, was unable to adopt the children because such adoptions were not legalized in Pennsylvania until 2002.

In 2001, after Ms. Jones and Ms. Boring broke up, Ms. Jones was recognized by the court as "in loco parentis," meaning that she had cared for the children sufficiently to have legal standing as a parent. Ms. Boring never challenged that standing.

Later that year, Ms. Boring was granted primary custody and filed for child support.

The children wanted to see both of their parents and did not prefer one over the other.

The trial court judge subsequently transferred primary custody to Ms. Jones because Ms. Boring violated the custody order several times and eventually moved out of state with the children.

Ms. Boring appealed and her lawyers argued that their client was not an unfit mother and should therefore be the primary parent.

Superior Court affirmed Judge Scott's ruling. Then the state Supreme Court refused to hear the case.

"These things are frequently framed as gay rights issues, in terms of the parents' rights. That's partly true. But the part of the story that's missing is it's very important for kids," said Leonore F. Carpenter, legal director for Center for Lesbian and Gay Civil Rights, which represented Ms. Jones, along with attorney Maureen Gatto, Lambda Legal and the National Center for Lesbian Rights.

"A child in a homosexual household deserves the same rights as a child in a heterosexual household," she said. But she emphasized that "this isn't just about gay families. Any [third party] who has been acting as a parent can apply this."

"What's the difference between a parent who happens to be the same sex as the biological parent? It's what the kid is used to," said Carol S. Mills McCarthy, a family court lawyer in Pittsburgh who has tried custody cases for many years.

Another veteran Pittsburgh family court lawyer, James E. Mahood, said the ruling was "nothing earth-shattering," nor does it set a new precedent.

"This is a good judicial decision. They decided it based on long-standing principles of law. It should not be controversial," he said.