Douglas represented Great Britain at the 2008 Olympics, in the 100 metres. In her first round heat she placed second behind Ivet Lalova in a time of 11.36 to advance to the second round. There she failed to qualify for the semi-finals as her time of 11.38 was only the fourth fastest time of her heat, causing elimination. She was also part of the Great Britain team which reached the final of the 4x100 metres relay, and which (along with the Jamaican team) were favourites to claim a medal. Jeanette Kwakye ran a good first bend in the final, but the British team failed to finish due to a mix-up in the changeover between Douglas and Emily Freeman. Jamaica also failed to finish after a similar error between Sherone Simpson and Kerron Stewart.