At the 2006 IPC World Championships she won three gold medals including the 50m backstroke S3, which she successfully defended four years later at Eindhoven.

Williamson was introduced to swimming as a child and began competing while at secondary school, having been terrified of water during her primary years.

[1] She was classified as a S3 classification swimmer and her first competitive meet as part of the Great Britain team was in 2001 at the European Championships in Stockholm.

[1] In 2002 Williamson travelled to Mar del Plata in Argentina to represent Great Britain at her first IPC Swimming World Championships.

In the 4x50m freestyle relay, Williamson was joined by team mates Jeanette Chippington, Mhairi Love and Jane Stidever.

Battling from a serious shoulder injury, which later required reconstruction, Williamson's ability to compete was questioned on numerous occasions.

In the final Williamson recorded a time of 1:06.75 which was enough to secure second place and her fourth career Paralympic silver medal.

She cited the quality of the next generation of athletes coming through the system would make a podium finish at the 2012 Paralympics in London difficult.