Lady Rosemary Spencer-Churchill 20th and 21st-century English noblewoman (b. 1929) Parents Mary Spencer-Churchill, Duchess of Marlborough John Spencer-Churchill, 10th Duke of Marlborough Children Simon Huntly Muir Alexander Pepys Muir Mary Arabella Muir Siblings John Spencer-Churchill, 11th Duke of Marlborough Lord Charles Spencer-Churchill Lady Caroline Spencer-Churchill Lady Sarah Spencer-Churchill Partners Charles Robert Muir