Martha Jefferson.
When Thomas Jefferson became President in 1801 his wife Martha had been dead nineteen years. During his two terms, Dolley Madison and his daughter Martha ("Patsy") helped with White House hostess duties as needed.
After Martha died in 1782, Jefferson rarely spoke of her. In his autobiography he said simply that he "lost the cherished companion of my life, in whose affections, unabated on both sides, I had lived the last ten years in unchequered happiness." There is a story that as Martha lay dying, Jefferson promised never to remarry. He never did.
Patsy described her father's grief: "he was led from the room in a state of insensibility by his sister, Mrs. Carr, who, with great difficulty, got him into his library, where he fainted, and remained so long insensible that they feared he would never revive. The scene that followed I did not witness, but the violence of his emotion, when almost by stealth, I entered his room at night, to this day I dare not trust myself to describe."