Adoption of Tammy

*206Greaney, J.

In this case, two unmarried women, Susan and Helen, filed a joint petition in the Probate and Family Court Department under G. L. c. 210, § 1 (1992 ed.), to adopt as their child Tammy, a minor, who is Susan’s biological daughter. Following an evidentiary hearing, a judge of the Probate and Family Court entered a memorandum of decision containing findings of fact and conclusions of law. Based on her finding that Helen and Susan “are each functioning, separately and together, as the custodial and psychological parents of [TammyJ,” and that “it is the best interest of said [Tammy]…