Complex sentence: Partner-in-crime/best friend of Jennifer Pierce, who also attends Garfield High School, is also the daughter of inspector Henderson, Kiesha will encourage Jennifer to challenge her image as the perfect principal's daughter.
Split into simpler sentences: Partner-in-crime/best friend of Jennifer Pierce, who also attends Garfield High School. The daughter of Inspector Henderson, Kiesha will encourage Jennifer to challenge her image as the perfect principal's daughter.