Despite Luke—who had to kill their last leader, Gabriel, to take over—being a fairly recent addition to their pack, Gretel remained extremely loyal to him and served as his second-in-command. Gretel used to call Gabriel "master"—a habit Luke did not like and tried hard to break; though she wouldn't budge on calling him with a title of respect, he eventually got her to just call him "sir". Gretel also served as one of the medics of the pack, being the one Luke called on to treat his wounds.
When she accompanied Luke and Clary to Valentine Morgenstern's hideout at the ruins of Renwick's Mental Hospital in August 2007, she was killed by Forsaken in the battle outside the hospital. Alaric, the third-in-command, immediately took her place and also defended Luke with his life and was also killed the same night.
Her wolf form was described as skinny with bright silver fur.
- City of Bones (first and only appearance)