Complex sentence: Her first big break came in 2001 on the Island of Martha's Vineyard during a Fourth of July Celebration hosted by local politicians related to her high school friend, where she and good friend Tony Rock (brother to Chris Rock) performed with an overwhelming response.
Split into simpler sentences: Her first big break came in 2001 during a Fourth of July Celebration on Martha's Vineyard hosted by local politicians related to her high school friend. She and good friend Tony Rock (brother to Chris Rock) performed, with an overwhelming response.