A Colorado Appeals Court ruled earlier this month that a man with a six-year father-child relationship was the child's parent for all legal purposes, including joint legal custody and visitation. Although it's not obvious that such a case would be a win for the children of lesbian couples, in fact the basis for the court's decision is applicable by analogy to the situation in which a non-bio lesbian mom raises a child with the child's bio mom.
Nicholas Rueda and Lavern Davis had been romantic partners. They separated. Lavern gave birth to a daughter, A.D., in 2001. Eleven months later, Davis and Rueda reconciled, and they lived together as a family until 2007. For the next year, A.D. spent several nights a week with Rueda. Davis discontinued the relationship in February 2008, and weeks later Rueda filed a parentage action. Davis conceded that Rueda "received A.D. into his home and openly held her out as his natural child." This made him a presumptive father under Colorado law.
The mother, Davis, argued that because Colorado defined the parent-child relationship as the legal relationship between a child and his/her "natural or adoptive" parents, that Rueda was not a parent because he was not a biological or adoptive parent. The court declined to interpret the statute in that manner since the "holding out" parentage presumption does not require a biological tie. The court explicitly cited a California Supreme Court ruling upholding parentage for a nonbio dad who raised the child with the child's biological mother; that case, in turn, provided support for the California Supreme Court's later ruling that the lesbian partner of a biological mom is also a child's parent if she takes the child into her home and holds the child out as her own. Hence my optimism that after this ruling Colorado courts will recognize dual parentage for a child raised by a same-sex couple.
This month the Michigan trial court ruling in favor of a non-bio lesbian mom also declined to interpret "natural" parent as requiring a biological tie. When people refer to the husband of a woman who gives birth as a "natural" parent they don't actually know that he is the child's biological parent. Like every word in a statute, "natural parent" has a legal definition. If a statute does not make biology a necessary component of "natural" parentage, then a court is free to consider other factors. And when a statute creates parentage for a person who receives the child into his home and holds the child out as his own, that can certainly be a woman as well as a man.