Before her series I Am Jazz debuts Wednesday night on TLC, the teen tells PEOPLE Now: “People think this was a choice, that one day I woke up and was like, ‘I’m a girl,’ but no – it’s just the way I was born. I’ve always been a girl.”
Among the biggest misconceptions about being trans, Jennings says, “Everyone always thinks it’s about the surgery, what’s between your legs, but … this is about what’s between your ears – and being transgender is the process of learning to love yourself and accept your difference. People have to understand that it’s not just a medical journey.”
As a transgender activist, the YouTube star has not shied away from addressing some detractors who have insisted she was “too young to transition.”
“They don’t define me – I define myself,” says Jennings. “At age 2, I knew I was a girl, and I really just kept pushing that thought forward to my parents.”
While she still believes gender is something you can explore as you get older, for her “it was dead-on, right from the start.”
RELATED VIDEO: Watch Jazz Jennings Create a DIY Mermaid Outfit
The 11-episode docuseries will focus on Jennings as she deals with the problems of any average teenager: friends, dating and family (including three older siblings and parents Greg and Jeanette).
Jennings – who was designated male at birth – became one of the youngest people diagnosed with gender dysphoria at age 5. She went public with her transition in 2007 and has since become a major spokesperson in the transgender community and has co-authored a book about her experiences growing up trans.
“She’s just so brave and courageous to come out with the public eye looking upon her,” Jennings says of Jenner, 65. “I think people are starting to open up their minds when it comes to accepting us for who we are, so I’m just so proud of her for being such a role model.”
I Am Jazz premieres Wednesday at 10 p.m. ET on TLC.