Big was born March 19, 1971, in West Berlin, Germany. The daughter of bankers, was hoping to pursue a career in architecture, furniture design, or even as the chancellor of Germany, her path took an unexpected twist when she was discovered by a modeling scout while sitting in a Berlin café in 1989. The scout wanted Nadja to pose for a travel catalogue, and although she was hand-picked out of a crowd, the beginning of her career was a failure. Nadja managed to sign with the Karin modeling agency, and signed a contract with Elite Modeling Management a year later. Nadja landed modeling gigs, but it wasn't until she bleached her hair platinum blonde for a prêt-à-porter collection that her career took off.

Everyone from Harper's Bazaar to Vogue came crawling, as both magazines featured portfolios on the "it" girl in modeling. By 1994, Nadja (now donning a cropped haircut) was the model for runways and magazine photo spreads. This was made clear with a 26-page Neiman Marcus shoot in Harper's Bazaar and consecutive Vogue photo shoots in 1994. One of the select few to appear on both the cover of Harper's Bazaar and Vogue US the same month, Nadja also joined the big name supermodels to appear in George Michael's Too Funky video, sharing the spotlight with Linda Evangelista That same year, the German beauty posed for the highly coveted Pirelli calendar.

Nicknamed the "blonde angel", Nadja's career as a supermodel can be seen in the list of advertisements and magazines she has appeared in. Her resume of advertisements reads something like this: Anne Klein, Christian Dior, Dolce & Gabbana, Gianfranco Ferré, Gianni Versace Couture, Giorgio Armani, GV Jeans, Joop!, Krizia, Karl Lagerfeld, Prada, Valentino, Versace Atelier, and Yves Saint Laurent. Nadja continues to model today (despite the fact that she has a child), and has most recently strutted down the catwalks for Chanel, Gianni Versace and Thierry Mugler.