Mallmann's international career began with the arrival of photographer Ellen von Unwerth in Brazil for Forum's 1996 winter campaign. Mallmann wasn't the main model in the campaign, but Von Unwerth turned her into the protagonist and nominated her for several jobs, such as the cover of the French Marie Claire with Patrick Demarchelier, the cover of the Italian Glamour magazine, and editorials for Harper's Bazaar and the Italian Vogue. Mallmann went to New York and returned to her country as a supermodel.
