Mason was born in Knowle, in the West Midlands in 1933.[3] She started to ride horses from a young age and got her first horse when she was seventeen years old.[3] In 1954, Mason became the first woman to be selected for the British three day eventing team.[3] In the same year, she won gold at the European Eventing Championships.[6]
Mason competed at two Olympic Games.[4] At the 1976 Summer Olympics in Montreal, she competed in the individual and team dressage events, finishing in 25th and 8th places respectively.[7][8] Twelve years later, at the 1988 Summer Olympics in Seoul, she competed in the same two events, finishing in 37th place in the individual event,[9] and 10th in the team event.[10] Mason was also a reserve for the 1984 Summer Olympics in Los Angeles.[3]
She retired from competing in 1991.[3] From 1975 to 1992, Mason was the chair of the British Horse Society Dressage Group,[4] and she was the team manager for Great Britain at the 1996 Summer Paralympics in Atlanta.[4] Mason continued to judge events until 2013.[3]
In January 2008, Mason was named an OBE for services to equestrian sport in the New Year Honours.[11] She died in March 2016, at the age of 82.[12]
