Complex sentence: Jean's paternal grandparents were Adam Hepburn, 2nd Earl of Bothwell and Agnes Stewart, and her maternal grandparents were Henry Sinclair, 3rd Lord St. Clair and Margaret Hepburn.
Split into simpler sentences: Jean's paternal grandparents were Adam Hepburn, 2nd Earl of Bothwell and Agnes Stewart. Her maternal grandparents were Henry Sinclair, 3rd Lord St. Clair and Margaret Hepburn.