Patricia Knatchbull, 2nd Countess Mountbatten of Burma
Patricia Edwina Victoria Knatchbull, 2nd Countess Mountbatten of Burma, Dowager Lady Brabourne, CBE, MSC, CD, JP, DL is a British peer and the third cousin of Queen Elizabeth II. She is the elder daughter of Louis Mountbatten, 1st Earl Mountbatten of Burma and his wife, the heiress Edwina Ashley, a patrilineal descendant of the Earls of Shaftesbury, first ennobled in 1661. She is the elder sister of Lady Pamela Hicks, and first cousin to Prince Philip, Duke of Edinburgh.
Mountbatten was born the daughter of a younger son of a marquess and thus had no courtesy title. She became the daughter of a peer , and thus obtained the courtesy prefix Honourable. When she married a baron, she obtained her husbands precedence, which happened to be higher than that of a viscounts daughter. When her father was raised to an earldom, however, her precedence remained the same, because the higher courtesy rank of an earls daughter cannot be claimed by the wife of a man who ranks as a peer in his own right. When her father died and she succeeded him as countess by special remainder, Patricia Mountbatten became a peer in her own right. Since her peerage was higher than her husbands, she was entitled to enjoy its higher title and precedence. By contrast, her younger sisters rank as an earls daughter outranked her husbands status as a commoner from August 1946 to August 1979 because when a peers daughter marries a commoner rather than a peer, she is allowed to retain the ran
Source: Wikipedia