MONTPELIER, Vt. (AP) – Battles over the custody of children between estranged spouses are nothing new. But this one involves a child born to a lesbian couple in a since-dissolved civil union.

And so far, it has produced dueling court rulings in Vermont, the first state to offer legal recognition to same-sex relationships, and Virginia, which has a law saying neither same-sex marriages nor civil unions carry the force of law in that state.

The case comes up for argument before the Vermont Supreme Court this week and before the Virginia Court of Appeals next week. Both supporters and detractors of same-sex marriage and civil unions say whatever the outcome, historians may one day see it as a landmark in the current debate over what laws should govern same-sex relationships and the children born to them.

“This case has significant implications for a number of reasons,” said Mathew Staver, a lawyer with Florida-based Liberty Counsel, which opposes same-sex unions. He said there have been other cases in which out-of-state courts have been asked to grant dissolution of Vermont civil unions, and refused because their states don’t honor such unions. In this case, “You have two state laws clashing for the very first time.”

If the Vermont and Virginia courts don’t resolve their differences, the case likely would go to the U.S. Supreme Court, the ultimate arbiter in instances when there is a clash between the highest courts in two states, Staver said. “This would have major precedential value.”

Jennifer Levi, a lawyer with Gay and Lesbian Advocates and Defenders who will represent Janet Jenkins at this week’s hearing, called that kind of speculation premature. She said she was hopeful for rulings from both the Vermont and Virginia courts that would allow her client visitation with the now 3-year-old girl at the center of the controversy.

Jenkins, now 40, and Lisa Miller, 36, both Virginia natives, fell in love in their home state, traveled to Vermont in 2001 just long enough to get a civil union and returned home. While they were living together in Virginia, Lisa – court papers refer throughout to the women by their first names – got pregnant by artificial insemination and gave birth in April of 2002 to a healthy baby girl. They named her Isabella.

The couple later decided to move to Vermont, where they lived for a little more than a year before deciding to break up. Filing for dissolution, Lisa filled out paperwork indicating that Isabella was the child of the civil union, a fact that Janet’s team is using to argue that under Vermont law, that makes Janet a parent of Isabella.

Lisa later changed her mind and asked Rutland Family Court Judge William Cohen to find that she was Isabella’s sole parent, a request the judge denied.

Meanwhile, Lisa had moved back to Virginia. She wanted out of the relationship with Janet and out of what she now calls “the homosexual lifestyle.” She had grown more religious, she said in a phone interview last week. “God had been laying it upon my heart that the homosexual lifestyle is wrong.”

Levi said Janet did not wish to be interviewed for this story.

Unhappy with Cohen’s ruling granting Janet visitation, Lisa and her allies took two lines of attack, appealing the Rutland court’s ruling – that’s the case before the Vermont Supreme Court – and going to court in Virginia and winning a declaration that Lisa was Isabella’s sole parent, with no obligation to Janet for visitation or anything else.

Federal law, particularly the Parental Kidnapping Prevention Act, is set up to block a parent unhappy with one state’s custody order from taking a child to another state’s court in search of a more favorable outcome. It says the second state must honor the first state’s ruling on custody and visitation, and Janet’s team is relying on this law in arguing that the Virginia court should have let the Vermont ruling stand.

“Lisa moved to Virginia in order to try to get the benefit of Virginia’s public policy” against recognizing same-sex relationships, Levi said. “But that can’t trump what federal law says about the respect for the first court’s decision.”

Staver said in an interview and in briefs filed in the Vermont and Virginia courts that it’s not that simple. He questions Cohen’s finding that Janet was a parent by virtue of the civil union alone, even though she never formally adopted Isabella.

He also argues science and geography. Lisa is Isabella’s biological mother, and Janet has no biological tie to her. Janet was artificially inseminated in Virginia, born in Virginia and lived in Virginia when the first court case was filed.

The court papers from either side, chock full of acronyms like PKPA for the Parental Kidnapping Prevention Act and DOMA for the federal Defense of Marriage Act, read like a legal game of “Can you top this?”

Janet’s team: The Parental Kidnapping Prevention Act requires Virginia to honor the Vermont court order.

Lisa’s team: Congress later passed the Defense of Marriage Act as part of the same chapter of federal law as the PKPA – meaning DOMA, which allows states to ignore civil unions or same-sex marriages performed in other states, trumps PKPA.

Janet’s team: Congress later amended and strengthened the PKPA without tying it to the DOMA, meaning DOMA’s disrespect for civil unions and same-sex marriages doesn’t apply to the question of whether one state should honor another’s custody orders.

In one instance, Janet’s Virginia lawyer, Joseph Price, appears in court papers to take pleasure in the fact that Vermont has civil unions, rather than full same-sex marriage. That’s an unusual position for a gay rights advocate, most of whom see civil unions as a half-measure on the way to marriage.

Price argues that his opponents can’t use DOMA to attack the parental rights that stem from Janet’s civil union, because DOMA talks only about marriage and never mentions civil unions.

As for what rulings might emanate in the months to come from the two V-state courts set to consider the case, Levi said, “What we’re really interested in is what’s in the best interests of a child.” In Levi’s view, that’s a continuing relationship with both of the women who nurtured her in her first months.

Lisa said she does not dwell on the outcome. “I give it to God. I don’t think about it one way or another. It’s in God’s hands.”