Complex sentence: Sarah Churchill was born in London, England, the second daughter of Prime Minister Winston Churchill and Clementine Churchill; she was the third of the couple's five children and was named after Winston's ancestor, Sarah Churchill, Duchess of Marlborough.
Split into simpler sentences: Sarah Churchill was born in London, England, the second daughter of Prime Minister Winston Churchill and Clementine Churchill; she was the third of the couple's five children. Sarah was named after Winston's ancestor, Sarah Churchill, Duchess of Marlborough.