Since September 2010 she has presented the Monday to Thursday editions of 19/20, the main evening news bulletin of France 3.
After two years in Australia, she became in February 2003 the substitute anchor for David Pujadas on the weekday editions of France 2's evening news programme 20 heures, a position she held until August 2006.
[1] During this period, Gaessler co-hosted election night coverage of the 2004 French regional and cantonal elections alongside Daniel Bilalian and, with David Pujadas, live coverage of the result of the French European Constitution referendum in 2005.
Gaessler later became the editor in chief and presenter of the weekly consumer news magazine C'est notre affaire on France 5.
In September 2008, she succeeded Marie Drucker as presenter of Soir 3 from Mondays to Thursdays on France 3.