In her debut Games, the 18-year-old, who began her swimming career with Keynsham Swimming Club and is still a member, won her favourite event, the 200m Individual Medley.
She finished more than two seconds ahead of Australia’s Alicia Coutts to set a Games and British record of 2:08.21.
Of her win she said: “I’ve trained so hard this year and that was the dream result.”
The swimmer, who was the youngest member of the Team GB swimming squad at the Olympic Games, is based at the University of Bath.
Her gold medal followed a hat-trick of silver medals in the 100m butterfly, 200m freestyle and 4x100m freestyle relay, and a bronze in the 4x200m freestyle relay.
Keynsham Amateur Swimming Club hailed Siobhan-Marie’s achievements and also praised club member Amelia Maughan who was part of the England team who took bronze in the 4×200 freestyle relay. Amelia also collected a silver medal for helping England qualify for the 4x100m freestyle relay final by swimming the anchor leg in the heats.
The club said: “Siobhan swam a storming 200 Individual Medley in the Commonwealth Games, breaking the Games record and winning the gold. Siobhan was miles ahead and just looked amazing from the start. She has been the fastest starter in all her races. Well done Siobhan, so proud of you.”
Messages of congratulations for Siobhan-Marie have been posted on the Bitton Village Facebook page with a call for the village’s postbox to be painted gold in her honour.
More than 100 Royal Mail postboxes were painted gold to celebrate Britain’s Olympic and Paralympic winners and plaques attached, naming the successful athlete and their achievement.