John P Ravilious gave the following summary. 
1.2 Elizabeth de la Hay was a nun.
'Elizabethae filiae meae moniali in prioratissa de Thikhede', had bequest of 20s. in her father's will (will of Peter de la Hay, dated feast of St. Valentine, 1345 (proved 31 Oct 1347) [Test. Ebor. I:12-13])
 Genealogy Medieval, [URL].