On Sept. 19, 2004, 14-year-old Rebecca gave a startling letter to her mother, Betsy.
"This is one of those stream of consciousness things that I write in the wee hours of the morning when I'm tired and unable to sleep. I was probably crying when I wrote it, but don't think that the tears blurring my eyes were blurring my judgment as well," Rebecca wrote.
"What am I? I ask myself this all the time. Right now what I believe myself to be is an FTM, or a female-to-male transsexual. A boy in a girl's body. What I want is for you to understand, and let me transition into the boy I really am."
The startling admission left Betsy shocked and bewildered.
"It was an out of body experience," she said. (The family's last name is not being used to protect their privacy.)
For Rebecca, the letter was the culmination of years of anguish over feelings that she had been born into the wrong body. She signed it, "Love, your son," -- a reflection of her deeply held conviction that she was a boy. (Click here to read the full letter).
"I can't quite explain it. It was just a feeling of being not quite in my body," Rebecca said. "When I was in kindergarten, I would tell people that when I grew up I wanted to be a boy. I didn't want to be astronaut, or a teacher. I wanted to be a boy."
Rebecca's parents, however, saw no signs that something was amiss with their youngest child. Raising their family in Los Angeles, the couple worked hard to make their two daughters, Rebecca and Anna, feel that they could do everything that boys could do.
So when Rebecca wanted to play with trucks with other boys, Betsy and her husband weren't troubled.
"I think I must honestly say that I was pretty oblivious to that," said Rebecca's father, Peter.
But it was excruciatingly clear to Rebecca -- even more so when she hit puberty. She felt awkward and uncomfortable when her breasts began to grow. Menstruation, which for most girls is a celebrated right of womanhood, served only to further alienate Rebecca from her own body.
"It didn't really feel like my body, or like this was my life-changing moment. It just seemed like this weird thing that was happening."
Confused, Rebecca went looking for answers, and in the seventh grade, she found them on the Internet. She finally had a word to describe what she was: transgender. She even found other children who struggled with the same feelings she did.
Rebecca had found clarity, but she kept the knowledge of what she was hidden for two more years. Finally, when she was 14 years old, Rebecca told her secret to her sister, Anna, via e-mail.
"I wrote back the same day saying, 'You know, I don't get it yet, but I love you with all my heart. You are my favorite person in the world, and absolutely, whatever you need,'" Anna said.
Anna and Rebecca had always been close. With her sister's support, Rebecca wrote her coming-out letter and gave it to her mother. Despite her initial shock, Betsy kept her composure, and even had the wherewithal to ask whether Rebecca had a new name. She was prepared. Rebecca became Jeremy.
"I didn't see her crying the day I came out," Jeremy said. "She held it in, which was kind of what I needed then. I needed to know that she still loved me. And that this wasn't going to bring her to tears."