From the Telegraph of 8 Oct 2020: The Earl of Haddington and Miss A.C.A Dessain - The engagement is announced between the Earl of Haddington, son of the Countess of Haddington and the late Earl of Haddington, of Mellerstain, Berwickshire, and Constanza, daughter of Simon and Catharina Dessain, of Inverkeilor, Angus.
The 14th Earl of HADDINGTON (b 1985) s of 13th Earl of HADDINGTON (1941-2016) and (Susan) Jane Antonia (b 1953) d of John HEYWORTH (1925-2012, gs of 3rd Baron TWEEDMOUTH (1874-1935), gt gs of 1st Earl of MIDLETON (1856-1942) and 2xgt gs of 10th Earl of WEMYSS (1818-1914) etc) and Susan Elizabeth Hamersley BURDER.
I take the prospective bride's father to be Simon James Francis DESSAIN (b Sept 1956) who has 9 appointments registered on the Companies House website, by his m to Catharina Mary Fredericka _ (also registered on the CH website)