On 6 July 1332 she was born, daughter of William de Burgh, 3rd Earl of
          Ulster, and Maud of Lancaster. She was her father's only daughter and
          was presumed to be his heir in his honours and, as such, in 1433
          became suo jure Countess of Ulster. In 1342, aged ten, she married the
          three-year-old Lionel of Antwerp who, in right of his wife, became
          Earl of Ulster. On 16 August 1355 their only child, Philippa, was
          born. On 13 November 1362 Lionel was created Duke of Clarence but, in
          1363, Elizabeth died in Dublin.
 

Source: Leo van de Pas