Theodosia Wingfield, nee Theodosia Anne Howard, Lady Powerscourt (1800-1836) was the daughter of was the daughter of Hon. Hugh Howard (son of Ralph Howard, 1st Viscount Wicklow) and Catherine Bligh. She became an evangelical under the influence of the staunch evangelical clergyman, Robert Daly, in 1819.
She married Richard Wingfield, 5th Viscount Powerscourt, son of Richard Wingfield, 4th Viscount Powerscourt and Lady Catherine Meade, in August 1822. Her husband died on 9 August 1823 at age 32, so she became a dowager at an early age. She died on 31 December 1836.
She was a close friend of John Nelson Darby and sponsored the Powerscourt prophecy conferences in the 1830s.
See this Wikipedia (English) article