MacGregor was selected to compete for Great Britain at the 2012 Summer Olympics in the newly created Elliott 6 metres match-racing event. She will compete alongside her sister Lucy MacGregor and Annie Lush. Together the three are nicknamed the "Match Race Girls". The event took place at the Weymouth and Portland National Sailing Academy with the round robin group stage being held from 29 July to 4 August 2012. They were defeated in the quarter finals of the Sailing at the 2012 Summer Olympics – Elliott 6m by the Russian team.