The peerage states Henry of Huntingdon died August 9, 1250 at Ashill, Norfolk, England. It also states he had (2) children by Ada de Huntingdon:
Henry de Hastings (son) who dies 1268/1269.
Eleanor de Hastings.
Ada is described as being "relict" of Henry meaning a widow. (From another source already quoted). Henry's death agrees with Welsh database of nobility citations. So widowed after 1250.