K.M. v. E.G. is a second-generation lesbian mother custody dispute. The women involved in these cases became parents through assisted conception, when one partner used semen from a known or unknown donor; through one partner’s sexual intercourse; or through adoption, when one woman became the legal adoptive parent because two women could not adopt together. The legally salient fact about these families was that only the woman who gave birth to or adopted the child was a legal parent. Some of the disputes that emerged in the 1980s occurred after the legal parent died, when her relatives filed for custody. Most disputes arose when the couple split, and the legally recognized parent denied her former partner all contact with their child.