On a spring day in 1993, Nancy Abrams helped her daughter dress for day care, packed her lunch, and said good-bye. Next she drove to court, where she learned that in the eyes of the law she was nothing more than "a biological stranger" to the child she helped bring into the world and raise. That was the last time she would see her daughter or hear her voice for five years.     The Other Mother begins as Abrams and her female lover decide to start a family together. With giddy anticipation, they search for a sperm donor, shop for baby clothes and crib, and attend childbirth classes. But despite their high hopes, the relationship begins to fall apart, and they separate when their daughter is a toddler. Problems between the two intensify until, shortly before her daughter's fifth birthday, Abrams loses custody.     In unprecedented depth, Abrams's compelling narrative examines the social, legal, and political implications of gay and lesbian parenting. Her haunting memoir asks the question, "What makes a mother?" It is a question that biological parents, co-parents, adoptive parents, step-parents, and divorced parents must each answer in their own way. In telling one woman's story, The Other Mother makes a solid case for legal protections, including marriage, for lesbian and gay families.