We're back, now, with barbara walters. Great to have you here, as always. You're here to share part of your edition "20/20," special day, tomorrow night. Special time, 8:00 p.M. This is the story of a... See More
We're back, now, with barbara walters. Great to have you here, as always. You're here to share part of your edition "20/20," special day, tomorrow night. Special time, 8:00 p.M. This is the story of a young girl facing something of a unique challenge. She really has. This is a little girl I've been following since she was 5 years old. And she's now almost 12. Her name is jazz. And I said, george, that she's a little girl. But she was born a boy. Jazz is what we call a transgender, which is people who feel they were born in the wrong body. It's also known as gender identity disorder. She's not gay. She's not a lesbian. And being transgender is not a phase. Her parents, jeannette and greg have known since she was very young that she was transgender. She has two older brothers and an older sister. She was female on her birth certificate. She was raised as a girl. She plays on a girls' soccer team. But now that she's entering puberty, george, she has a whole new list of problems. You are getting to the age, jazz, when girls and boys date. Are you attracted to girls or to boys? I'm attracted to boys. Are you afraid you might not have dates with boys? I am a little bit. But if any of the boys decline me because of my situation, then I just know they're not right for me at all. Reporter: If you think life is complicated, try dealing with a transgender girl texting a boy she just met at school. She's made a new friend. And it's a boy. I tell her, you know, you're going to have friends that are boys, they need to know immediately. I'm transgender. But I was a boy, but became a girl. I have a girl brain but a male body. Reporter: A few moments later, the boy responds, obviously confused. He just sent me, you have a girl body, right? That's a difficult question to ask. Why don't you tell him to watch the videos. Reporter: Jazz texted him back, to watch this online video of her. I think like a girl. But I just have a boy body. That's a cute video. What parts of a boy do you have? What are you going to say? The "p" word. Reporter: Like a tattoo that won't rub off, the "p" word is likely to follow jazz everywhere. I don't care what he thinks about me, if it's that -- if it's good, I'll be happy. Wait until you hear what she's up to. Reporter: Greg's been down this road before with his oldest daughter.But advising a transgender tween with a crush is new territory. What did he say? He accepts me for who I am. That's sweet. Are you happy? Now, I'm texting my friends about it. I have to get something. Reporter: What part of being transgender hurts you the most? My genitalia because right now, I feel like a girl. But when I look down there, it reminds me. Reporter: That must feel very bad for you. Yeah. What a set of challenges, barbara. There's so much love and so much communication. Wonderful parents. And they are doing this and allowing this with jazz because there are other children and adults, who suffer from what is called gender identity disorder. And she wants parents to love their children and to know that they're okay. And they're still lovable. Boy, it could be so tough for her in those teen years. She has a lot of choices to make. Right now, she's on hormone blockers that stop the testosterone. And she has to decide if she wants to do estrogen, which will make her more feminine. And at some point, around the age of 18, she has to decide if she wants gender reassignment surgery. What a story. Barbara, thanks very much. You can see the whole story tomorrow night on a special edition of "20/20." Address, at 8:00 p.M. Eastern. Look at this basement.
This transcript has been automatically generated and may not be 100% accurate.