Mama, something went wrong in your tummy. And it made me come out as a boy instead of a girl.

When Marlo Mack's three-year-old utters these words, her world splits wide open. Friends and family, experts, and Marlo herself had long downplayed her "son's" requests for pretty dresses and long hair as experimentation--as a phase--but that time is over. When little "M" begs, weeping, to be reborn, Marlo knows she has to start listening to her kid.

How to Be a Girl is Mack's unflinching memoir of M's coming out--to her father, grandparents, classmates, and the world. Fearful of the prejudice that menaces M's future, Mack finds her liberal values surprisingly challenged: Why can't M just be a boy who wears skirts and loves fairies? But M doesn't give up: She's a girl!

As mother and daughter teach one another How to Be a Girl, Mack realizes it's really the world that has a lot to learn--from her sparkly, spectacular M.