Caitlin won two gold medals at the 2006 Commonwealth Games, taking victory in the 200m Freestyle and 400m Freestyle. Representing Great Britain, she won bronze medals in the 400 m Freestyle at the 2005 World Championships and 2006 European Championships. She has also competed at three Olympic Games and reached the Olympic 200 m Freestyle final in 2008 and 2012. She is a former British record holder in the 100 m, 200 m and 400 m Freestyle.
She graduated with a politics degree from Loughborough University in 2011 and is currently Chair of the Team Scotland Youth Trust.