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Marchioness of Thomond
Mary Palmer (1750 – 6 September 1820), Marchioness of Thomond, was a member of the British gentry and by marriage of the Irish peerage.
On 21 July 1792 she became the second wife of Murrough O'Brien, Earl of Inchiquin, later Marquess of Thomond, who had been widowed in 1790. She was painted at least three times by her uncle Joshua and as the chief beneficiary of his will she was able to pay off her husband's debts, though they had no children.