The character is the daughter of original character Viki Lord Buchanan (played by Daytime Emmy Award-winner Erika Slezak since 1971), and gave Williamson the opportunity to portray Jessica"s alternate personalities "Tess", from 2005 to 2006 and again starting in 2008 and 2011.
After graduating from Bayview Glen School, she completed her education at the University of Toronto.
She played the role of Jessica Buchanan on the American Broadcasting Company soap opera One Life to Live from February 5, 2003 until the series cancelation in 2012. Williamson had previously auditioned for a role on OLTL but was rejected because of her resemblance to actress Erin Torpey, who was playing Jessica Buchanan on the show at the time. When Torpey resigned in January 2003, Williamson was remembered by the casting department and offered the role of Jessica.
In 2009, Williamson appeared as Brandeis on Gossip Girl in the episode "The Grandfather: Participant II".
She reprised the role in the 2010 episode "The Empire Strikes Jack". In 2012, Williamson joined the cast of Haven as Doctor Claire Callahan for Season 3, which began airing in September 2012.
In 2013, Williamson appeared in flashbacks as Vivian Banks, the murder victim in the National Broadcasting Company television series Deception. In 2015, Williamson appeared as April Littleton, a famous photographer going back to her hometown, in Portrait of Love, which premiered on Hallmark Channel on March 7.
