Complex sentence: His sister, Sylla, was married to Dinshaw Maneckji Petit, the second baronet of Petits and his niece, Rattanbai Petit, was the wife of Muhammad Ali Jinnah, who later became founder of Pakistan in August 1947.
Split into simpler sentences: His sister, Sylla, was married to Dinshaw Maneckji Petit, the second baronet of Petits. His niece, Rattanbai Petit, was the wife of Muhammad Ali Jinnah, who later became founder the of Pakistan in August 1947.