Complex sentence: Her work attracted the attention of author Katherine Anne Porter, who became a mentor to Welty and wrote the foreword to Welty's first collection of short stories, "A Curtain of Green", in 1941.
Split into simpler sentences: Her work attracted the attention of author Katherine Anne Porter. Porter became a mentor to Welty and wrote the foreword to Welty's first collection of short stories, "A Curtain of Green", in 1941.