Rix was born on the Central Coast of
New South Wales. She participated in numerous amateur musical theatre productions from the age of 4. She began to perform throughout Sydney as the lead singer of a pop band at the age of 18. Rix then moved to Melbourne at the age of 21 to devote herself to musical theatre and was cast in a number of commercial projects. Rix moved to
Osaka, Japan after being cast as the Bride of Frankenstein in
The Monster Rock and Roll Show at Universal Studios Japan. In July 2006, she was cast as
Elphaba in the USJ mini version of the Broadway musical
Wicked, which required her to perform parts of the show in Japanese. Throughout the audition process, she met and performed for
Stephen Schwartz,
Winnie Holzman and
Marc Platt. She performed in this role for a year before returning to Melbourne. Rix was cast as the standby for Elphaba in the Australian premiere of
Wicked which opened in
Melbourne on 12 July 2008 and ran through 9 August 2009. The show was then transferred to
Sydney, opening on 12 September 2009. Due to the illness of
Amanda Harrison, Rix had many opportunities to perform the role of Elphaba, and on 9 February 2010, after an extended leave of absence, Harrison announced that she would not be returning to the show. The role was then offered to Rix, who continued to share it with Australian theatre actress
Pippa Grandison. They starred alongside
Lucy Durack in the role of
Glinda. Rix generally performed in four of eight shows a week, with the remaining four played by Grandison and later, Patrice Tipoki. Rix continued to be the first billed Elphaba, featuring on displays outside the theatre and appearing at most events and press interviews. These included the 2008 Carols by Candlelight, Melbourne's Federation Square and Town Hall, 2009 Australian
Ethnic Business Awards, 2009 QANTAS Business Awards, AFL pre-match entertainment performances, the ANZ Rob Guest Endowment Fund Concert, the Kerri-Anne Kennerley morning TV show, Sydney's Carols in the Domain 2009, the 2010 Telethon, and the 2010 Carols by Candlelight.
Wicked closed in Sydney on 26 September 2010, with Rix playing Elphaba. Rix again played the role of Elphaba on the show's first Australian Tour, which, after delays due to flooding, began in
Brisbane on 25 January 2011. In 2011, Rix was nominated for a Helpmann Award for "Best Female Actor in a Musical" for her portrayal as Elphaba in
Wicked. Rix played Elphaba again on the Asian tour of
Wicked, which began in
Singapore from 7 December 2011. After a four-month engagement there, the tour visited
Seoul. Previous Australian understudy
Suzie Mathers took over the role of Glinda full-time at the start of the Asian tour. Rix reprised her role as Elphaba in
Auckland,
New Zealand as of 21 September 2013 at the
Auckland Civic Theatre. After Auckland she traveled to
Manila,
Philippines to perform there. Rix continued to play the role for the 10th Anniversary return tour in Australia, performing in Melbourne, Sydney, Brisbane and Perth. During the tour, she reached a milestone by performing the role of Elphaba for 1000th time in October 2014. It was announced mid 2015 that Rix would play the role Lucy, in the Australian production of
Jekyll & Hyde the musical, however the production has been postponed indefinitely. Rix went on to play the role of Molly Jensen in the Australian tour of
Ghost the Musical. In 2017, it was announced that Rix will appear in the Australian tour of
Andrew Lloyd Webber's updated version of
The Wizard of Oz. In 2017, Jemma played the role of Teen Angel in the Australian arena production of the musical
Grease (musical) when it toured to Adelaide and Newcastle. In mid 2018, Jemma joined the cast of Opera Australia's 'Evita' in the role of Eva Perón. She performed this role in Melbourne and Sydney. In October and November 2019, Jemma starred as Lucy in
Jekyll & Hyde with Anthony Warlow and the Melbourne Symphony Orchestra. It was announced on 15 February 2020 that Rix will play the role of Elsa in the Australian production of
Frozen in Sydney alongside
Courtney Monsma as Anna. ==Personal life==