The last one was won by her husband Scott Brennan in the double sculls in Beijing.
A Canberra doctor, he didn't make it to Rio but watched on television as Brennan blitzed the final, leading from start to finish to beat home American Genevra Stone and China's Jingli Duan with highly-fancied Kiwi Emma Twigg fourth.
Although he wasn't in the stands the pair shared a special moment when their wedding song, Uptown Funk by Bruno Mars, played as she walked to the medal dais.
"I think it was just one of those moments. I think it was meant to be," Brennan said.
After Australian rowers failed to pick up any gold in London and there were two silvers this week in Rio, the pressure was on the world champion to deliver.
Brennan said her plan was always to go out fast, aware that a strong cross-wind through the last section of the course would make it difficult for others to catch her.
Australia has won silver medals in track cycling and rowing, with Dane Bird-Smith claiming bronze in the 20km race walk as track and field gets underway.
