Gerg grew up in Lenggries and started for SC Lenggries. The slalom specialist was placed in the top ten ten times in the Ski World Cup . Her best result - after 13 years in the World Cup - was second place in Val-d'Isère on December 21, 2006. She took part in four World Championships and two Olympic Winter Games. At the 2006 Games in Turin , she was seventh in the slalom .
She won six German championships between 1997 and 2003, five in slalom and one in giant slalom.
On September 12, 2007, she announced her retirement from alpine racing due to a persistent injury in her right knee.