In Between by Jane Hoppen

Never have there been only two genders—male and female. A third gender, denied by society and hidden by the medical community, has always existed, and that is what Sophie Schmidt discovers when, at the age of fourteen, she learns the truth of how she was born. Sophie then embarks on a journey to learn more about her true self and to find others born like her. When Sophie moves to New York City, she enters the world of gays and lesbians, as well as those who are transgender and transsexual. Searching for her own place in society, her journey leads her to Alice Parker, and Sophie takes the final steps to accept herself enough to allow another to love her.