Complex sentence: Her paternal grandparents were John VIII, Count of Vendôme and Isabelle de Beauveau, and her maternal grandparents were Peter II, Count of Saint-Pol, and Margaret of Savoy.
Split into simpler sentences: Her paternal grandparents were John VIII, Count of Vendôme and Isabelle de Beauveau. Her maternal grandparents were Peter II, Count of Saint-Pol, and Margaret of Savoy.