Transgender teen and 'I Am Jazz' star Jazz Jennings on sharing the final steps of her transition journey: her gender confirmation surgery

It's a dream she’s had since she was 2 years old.

"When I was 2 years old, I went up to my mom and asked her, 'When is the good fairy going to come with her magic wand and change my penis into a vagina?'" Jazz Jennings, 18, told ABC News' "Nightline" co-anchor Juju Chang.

For Jazz, that dream became a reality. This past June, she underwent her gender confirmation surgery -- a procedure that, in her case, essentially re-fashioned male genitalia into a female equivalent.

"It was like a dream. It was. This is a moment that I had always envisioned and just experiencing it was so surreal. I was like I can't believe this is happening," Jazz said.

Jazz, who is from Florida, is one of the most well-known transgender teens in the country, carrying the torch on behalf of trans rights for the last decade.

Known for her relentless advocacy -- from gender neutral bathrooms, to playing school sports -- she’s tackled some of the most divisive issues for trans kids head on.

"From the time I was six years old, I've been sharing my story. And you know at first I thought, 'Okay, this is all going to come to an end one day and then I'll be able to live my life.' But more and more I realized that I was given this platform for a reason and that I have a strong and powerful voice," Jazz said.

When asked about whether living her life in the public has made it easier or harder to be a trans teen, Jazz said, "It just depends."

"I think for me, I've always been so honest about who I am as a person. And being transgender, I feel like it's something that I couldn't hide no matter what. Don't have to explain myself or the fact that I'm transgender to people who haven't met me before. So it's kind of-- I like that about being public," she said.

Her journey has been documented on her award-winning TLC reality show, "I Am Jazz," which returns for a fifth season on Tuesday, Jan. 1, 2019.

She shared when she, along with her parents, decided to medically intervene with hormone blockers when she was 11, pausing any male development. And then, when she was on the verge of high school, she began taking the female hormone, estrogen.

"I have no regrets because it allowed me to prevent myself from going through male puberty," Jazz said. "I feel like that's why my dysphoria hasn't been so bad is because I look in the mirror, and I see the girl that I am on the inside. But not every transgender person has the opportunity to do that."

In many ways, her journey has all led up to this moment. For Jazz, her gender confirmation surgery is what she says is "the final step of transitioning."

"This is really the last thing that will validate my identity as a woman. There is nothing else after this. I just get to be myself, be in the body that I've always wanted. And then I can live my life as just Jazz," she said.

For years, Jazz's willingness to share intimate details has been her calling card, and this milestone is no different.

"I've been criticized for sharing too much information, and yeah, it is personal and uncomfortable for some individuals. But how are we going to learn if someone doesn't step up to the plate and share their story and personal details," Jazz said.

When she first shared her story with ABC News’ Barbara Walters in 2007, Jazz was just 6 years old and one of the youngest documented cases of an early transition from male to female. Jazz started her transition at the age of five.

The Jennings family, who have three older children, were already at the time facing backlash for allowing Jazz, at such a young age, to present herself as trans. Ten years later, the family said they still find themselves defending that decision.

When asked how she would respond to people who might think her parents brainwashed her or that she was too young to know, Jazz said, "I really, really hate it."

"And hate's a strong word. But I hate it when people are, like, 'My parents abuse me into being transgender because they wanted another girl, not a boy.' And no, that's not how it was. This was all me. This is how I felt. And I was the one telling them that, 'I'm a girl, I'm a girl,'" Jazz said. "They just embraced and loved me for who I was. And they didn't force me to do anything. They never force me to do anything."

In the upcoming season of "I Am Jazz," viewers will get to see major milestones in her life, including Jazz attending her first prom, celebrating her 18th birthday and the final steps of her transition.

The surgery came with obstacles. Jazz said her doctor requested that she lose 30 pounds before the surgery.

"And that was really, really challenging because I had an addiction to food. And it was something that gave me comfort. And I had to let that go because the surgery is so much more important to me than any slice of cake or pizza," Jazz said.

The surgery was also complicated by Jazz being at the forefront of so many medical options now available to transgender kids, like the hormone blockers and hormone therapy she said helped save her life.

"Being on the blockers is something that I don't regret at all. But the only, you know, downside to it was that I didn't have enough growth down below. So there wasn't enough tissue to work with when it came to the surgery," Jazz said. "And it was very challenging to find a doctor, a surgeon who was willing to perform the operation on me just 'cause I'm such a difficult case."

Jazz and her family sought out a brand new, groundbreaking technique.

"They’re using the tissue I have, the peritoneum, and also, they may take a skin graft as well. I say it's going to be like a patchwork vagina, Franken-vagina," she said laughing. "So yeah, as long as it's functional, that's all that matters."

She added, "And I want it to look somewhat pretty, just 'cause it's my body."

"Nightline" caught up with Jazz nine weeks after her surgery. Though she was on her way to a full recovery, getting there wasn't easy.

"There was just an unfortunate event and setback where things did come apart, and there was a complication," Jazz said. "I had to come back in for another procedure, but it was just all part of the journey. The good thing though is that it was only cosmetic and external so it wasn’t too dramatic."

"My life wasn’t in danger. I had the guidance of two incredible surgeons, and they really just supported me throughout the entire process and took control over the matter," she added.

Jazz hopes her surgery will help pave the way for the next generation of trans girls seeking to have the same surgery. With the surgery behind her and now in her senior year of high school, Jazz's future is coming into focus for her, including what she wants to do after college.

"I've been thinking about that more and more lately. And I mean there's really no pressure for me to decide anything right now. However I'm thinking about focusing on like sociology and gender studies. I am finding myself becoming more and more passionate about the gender binary of this world and just the difference between gender and sex and helping people understand that so that all, you know, gender nonconforming individuals can be more accepted in this world," she said.

Jazz said she's thought more about continuing her advocacy.

"I think it really just depends on what direction my life takes. But more and more I'm thinking about just continuing my advocacy," Jazz said. "My passion is reinvigorated not just for trans rights but for equality for everyone and I really think that this world needs some changing, because we are not in a good place as a society right now, and I think if people could open their eyes and realize that if we choose a path of love, of accepting one another and embracing our differences."

Watch the full story on ABC News' "Nightline" TONIGHT at 12:35 a.m. ET.