Complex sentence: She was the most in-demand model during the June Rio Fashion Week, walking 35 of the 39 fashion shows and has since then walked for several designers including Burberry, Karl Lagerfeld, Ralph Lauren, Vera Wang, and Vivienne Westwood.
Split into simpler sentences: She was the most in-demand model during the June Rio Fashion Week, walking 35 of the 39 fashion shows. She has since then walked for several designers including Burberry, Karl Lagerfeld, Ralph Lauren, Vera Wang, and Vivienne Westwood.