Kerr started her career at age 15 with Perth Glory where she played from 2008 to 2012, before transferring to Sydney FC. In 2013, she joined the Western New York Flash for the inaugural season of the NWSL and helped lead the team to win the NWSL Shield. She later played for Sky Blue FC and the Chicago Red Stars in the same league. Kerr earned her first senior international cap in 2009 at the age of 15 and has represented Australia at the 2010, 2014, and 2018 AFC Women's Asian Cup tournaments. On the world stage, she has been in the Australian squad since 2009 and competed at the 2011, 2015, and 2019 FIFA Women's World Cups as well as the 2012, 2016 and 2020 Summer Olympics.