Christine Connelly, a member of the board of directors for the Boston Alliance of Gay, Lesbian, Bisexual, and Transgender Youth, stated, "She was the first young person who picked up the national spotlight, went on TV and was able to articulate her perspective and point of view with such innocence.

[3][7] She stars in the TLC reality TV series, I Am Jazz, which premiered in 2015 and focuses on her daily life with her family and the challenges she faces as a transgender person.

"[12] Jennings was assigned male at birth and was diagnosed with gender dysphoria by age four, making her one of the youngest publicly documented people to be identified as transgender.

In 2007, Jennings's parents founded TransKids Purple Rainbow Foundation to assist transgender youth; she is an honorary co-founder of the organization.

[19][20] That same year, in a follow-up interview with Barbara Walters on 20/20, they discussed Jennings's two-and-a-half-year battle with the United States Soccer Federation (USSF), the governing US body for the sport, to allow her to play on girls' teams.

Aided by the National Center for Lesbian Rights, she succeeded in changing the USSF's policies to allow trans students to play.

[36] The same year, Jennings voiced a teenage transgender character, Zadie, in the season finale of the Amazon Video animated series Danger & Eggs, who sings about acceptance, helping the two protagonists understand the meaning of a chosen family.

[37][38][39][40] Jennings described the experience as "groundbreaking," saying she was proud to be part of the show, especially in an episode that takes place at "a Pride event," saying it makes the role significant, meaningful, powerful, and special.

[44] In 2012, Jennings discussed her sexual orientation with Barbara Walters during her 20/20 interview, saying she was romantically attracted to boys and that she harbored some apprehension about dating because of her transgender identity.

In a Q&A video on her YouTube channel in July 2014, Jennings said that she was pansexual, and that she loved people "for their personality", regardless of their sexual orientation and gender.

[46][47] In an interview published in the April 11, 2018, issue of People, Jennings said that, per her surgeons' instructions, she had lost at least 30 pounds (14 kg) in order to have gender confirmation surgery, which was scheduled for June 20, 2018.