Marks has won a gold medal at the 2015 Military World Games and four gold medals at the 2016 Invictus Games. After the ceremony, she privately asked Prince Harry, who had awarded her her Gold Medals, if he could present one of her Invictus gold medals to the Doctors and Nurses of Papworth Hospital who had saved her life. She qualified for the 2016 Summer Paralympics by clocking a time of with 1:28.54 at the U.S. trials, which was only 0.01 seconds short of the world record. She won an individual gold and a relay bronze medal at the Paralympics.