She competed in the City to Bay Run in 2010, finishing first. That year, she also competed at the Nanning, China hosted World Half Marathon Championships. She ran her first marathon in March 2012, where she set an Olympic A qualifying time of 2 hours, 31 minutes. In 2012, her training regime included running up to a week. On her light training days, she ran . Trengove was selected to represent Australia at the 2012 Summer Olympics in the women's marathon. She was the third South Australian athletics competitor to qualify for the Games, and prepared for them by training in Adelaide. She finished the Olympic marathon in 39th place with a time of 2:31:17, 8 minutes and 10 seconds behind the first-place finisher Tiki Gelana. At the 2014 Commonwealth Games, she won the bronze medal, running a then personal best of 2:30:12. She came 22nd in the same event at the 2016 Rio de Janeiro Olympics in a time of 2:31:44. She finished ninth in the 2017 IAAF World Championships marathon in a time of 2:28:59. This was the best performance by an Australian woman in a World Championship.