The correct answer is: Susie O’Neill.
Susie O’Neill is an Australian former swimmer who won 11 gold medals at the Commonwealth Games, more than any other athlete in history. She also won 14 Commonwealth Games medals overall, second only to Australian swimmer Ian Thorpe. O’Neill won her first Commonwealth Games gold medal at the age of 14 in 1990, and her last at the age of 27 in 2006. She is a four-time Olympian, and won three gold medals at the 1996 Summer Olympics in Atlanta.
Graham Smith is a Scottish former swimmer who won six gold medals at the Commonwealth Games. He won his first gold medal at the age of 17 in 1970, and his last at the age of 25 in 1978. Smith is a two-time Olympian, and won a silver medal at the 1972 Summer Olympics in Munich.
Petria Thomas is an Australian former swimmer who won five gold medals at the Commonwealth Games. She won her first gold medal at the age of 17 in 1994, and her last at the age of 25 in 2002. Thomas is a two-time Olympian, and won a gold medal at the 2000 Summer Olympics in Sydney.
Mitchell Brown is an Australian swimmer who has won four gold medals at the Commonwealth Games. He won his first gold medal at the age of 19 in 2014, and his last at the age of 23 in 2018. Brown is a two-time Olympian, and won a silver medal at the 2016 Summer Olympics in Rio de Janeiro.