Complex sentence: Her maternal grandparents were Charles Bingham, 4th Earl of Lucan and Lady Cecilia Catherine Gordon-Lennox, a daughter of Charles Gordon-Lennox, 5th Duke of Richmond and Lady Caroline Paget.
Split into simpler sentences: Her maternal grandparents were Charles Bingham, 4th Earl of Lucan and Lady Cecilia Catherine Gordon-Lennox. Catherine was a daughter of Charles Gordon-Lennox, 5th Duke of Richmond and Lady Caroline Paget.