Complex sentence: She made her debut on the Paris and Milan runways during the Spring 2007 season and has since walked in runway shows for Christian Dior, Louis Vuitton, Ralph Lauren, Chanel, and many others.
Split into simpler sentences: She made her debut on the Paris and Milan runways during the Spring 2007 season. Since then, she has walked in runway shows including Christian Dior, Louis Vuitton, Ralph Lauren, Chanel, and many others.