D and P are two women who met and became involved in a romantic relationship. P moved into D's home in February 1995 and lived there until May 2, 2004. They discussed the possibility of executing joint wills with an attorney but never did so. They were beneficiaries of one another's life insurance policies. In 2004, they opened a joint account to process their joint bills. After failed attempts for D to have a child via artificial insemination and in vitro fertilization they decided to adopt a child from a foreign country. Kazakhstan did not permit two women to adopt the same child, so they decided that D would be the adoptive parent. P participated in the adoption process and accompanied D to Kazakhstan. Only D legally adopted the child. P took paid adoption leave from her employer and stayed home for nearly two months. D then began to work from home so that she could stay home with A.N.S. P enrolled A.N.S. as her dependent under the employee benefit plan so that A.N.S. would have medical, dental and vision coverage as well as spending accounts for health care and dependent care. The parties shared the expenses to care for and support A.N.S. In June 2003, they consulted an attorney for P's adoption of A.N.S. P would have to care for the child for one year in order for the Family Court to permit the adoption. P did not pursue formal adoption after she had lived with A.N.S. for more than one year. On June 22, 2004, P filed a petition for custody of A.N.S. in the Family Court. P filed a motion for a temporary visitation order. D filed a motion to dismiss on the same day. P filed a motion to amend her petition for custody, requesting permission to include a request for a determination of parentage under the DUPA in addition to her assertion of her right to seek custody/visitation as a de facto parent. D denied that P had standing to bring an action for adjudication under the DUPA because P lacks a biological tie to A.N.S. The Family Court granted P's motion to amend her petition to include a determination of parentage. The Family Court determined that P had standing to petition for custody as a de facto parent and denied D's motion to dismiss. The Family Court granted P joint legal and physical custody of A.N.S. D appealed.