Complex sentence: Her paternal grandparents were Jean I de Béthune, Seigneur de Locres, and Jeanne de Coucy, and her maternal grandparents were Jean VII de Ghistelles and Marguerite de Reingleset.
Split into simpler sentences: Her paternal grandparents were Jean I de Béthune, Seigneur de Locres, and Jeanne de Coucy. Her maternal grandparents were Jean VII de Ghistelles and Marguerite de Reingleset.