DOVER, Del. (AP) – The state Supreme Court has been asked to decide whether a lesbian should be allowed to share custody of three children to whom her former partner gave birth.

Family Court Judge Mark Buckworth ruled last year that, as a “de facto parent,” Susan Symes had standing to petition for custody of triplets born in 1997 to Elizabeth Symes, who during their nine-year relationship legally changed her surname to that of her partner.

Elizabeth Symes argued that Susan, who gave birth to a fourth child in 2001 using sperm from the same anonymous donor used by Elizabeth, did not meet the definition of parent under state law and therefore had no legal basis to petition for custody of the triplets.

In May, however, the court awarded joint custody of the triplets to both women, who began their relationship in 1994 and separated in 2003.

In a brief filed with the Supreme Court, Elizabeth Symes, whom the children called “Mommy,” argued that the trial court judge, ruling in a case of first impression in Delaware, went beyond legislative and statutory limits in granting custody to Susan, whom the children called “Mommy Sue.”

“The petitioner in this matter has no standing. The petitioner is not the natural or adoptive parent,” wrote Elizabeth’s attorney, Lois Dawson, who suggested that the Family Court had carved out a special exception in the law for custody issues involving same-sex couples.

“It is a means to permit a special privilege not afforded other similar classes: foster parents; the second husband/wife who has assisted in raising a child for a number of years and divorce occurs; adoptive parents; a person who lives with a biological parent without the benefit of the legal relationship of marriage and is not in a gay/lesbian relationship; relatives who voluntarily raise a child for a number of years with the parents [sic] approval, etc.,” she wrote.

Attempts to reach Dawson for comment were unsuccessful.

Courtney Joslin, an attorney for the National Center for Lesbian Rights in San Francisco, which is representing Susan Symes along with the New York-based Lambda Legal Defense and Education Fund, rejected the notion that the court had made an exception for gays and lesbians.

“We’re trying to make sure that the same rules that apply to the children of different-sex couples are applied equally to the children of same-sex couples,” she said.

In a brief filed with the Supreme Court, Susan Symes’ lawyers argued that the two women had agreed that each would become pregnant through artificial insemination, that they had jointly selected the names of the triplets, and that they agreed to raise the children together and share parenting responsibilities. They also noted that Susan was ordered in June to pay more than $700 a month in child support.

“Delaware law does not limit the means of establishing parentage to biology and adoption,” they wrote. “When two people deliberately bring a child into the world with the intention of being parents, the law should hold them legally responsible, regardless of the method of conception.”

Under Delaware law, a non-biological third party usually does not have standing to petition for custody of a child unless there are exceptional circumstances involving dependency or neglect. Exceptions also are made for a stepparent seeking custody after the death or disability of a child’s custodial parent.

Courts in Delaware and other states also have ruled that adults who are not biological or adoptive parents but who have developed close physical and psychological bonds with children in a family context can be considered “de facto” parents.

In 2001, for example, a Family Court judge in Delaware ruled that the male partner of an adoptive father of two children was a “de facto parent” and thus had standing to seek adoption of the children as a stepparent. The following year, a Family Court commissioner ordered a Newark woman to begin making child support payments for her estranged lesbian partner’s 5-year-old son.

Under a 2002 revision of the Uniform Parentage Act adopted by the General Assembly in 2003, a man who consents to assisted reproduction by a woman with the intent to be the parent of the resulting child is considered a parent of that child. The Delaware Parentage Act also states that a man who lives in the same household as a child for the first two years of the child’s life and openly holds out the child as his own is presumed to be the father.

Susan Symes’ attorneys note that provisions of the Delaware law regarding determination of paternity also apply to determinations of maternity.

“The statute supports fully my client’s position that she is a parent in the case,” said Suzanne Seubert, a Wilmington attorney representing Susan Symes.