Mary Sidney (née Dudley, 1530–1535 - 1586). Lady-in-waiting at the court of Elizabeth I, and the mother of Sir Philip Sidney, Robert Sidney and Mary Sidney Herbert, Countess of Pembroke. Wife of Henry Sidney. She was one of Queen Elizabeth's most intimate confidantes during the early years of her reign. Her duties included nursing the Queen through smallpox in 1563 and acting as her mouthpiece towards diplomats.
Her brother Lord Guilford Dudley was the teenage husband of Lady Jane Grey.