The following has been copied from a soc.genealogy.medieval post by Douglas Richardson in 2013.
"It has been claimed by various visitation sources, a Lumley family monumental pedigree in Chester-le-Street, Durham, and an early pedigree dated c.1505 that Thomas Lumley married a bastard daughter of King Edward IV. Several of these sources (including the earliest one dated c.1505) do not state the given name of Thomas Lumley's wife. However, several of the visitations including one as early as 1530 claim that the name of his wife was Elizabeth.
That the given name of his wife was actually Margaret, not Elizabeth, is proven by a contemporary license recorded on Membrane 8 of Roll 1 of William Dudley, Bishop of Durham. An abstract of this record was published many years ago in Annual Report of the Deputy Keeper 35 (1874): 134. Mention of this record was made by the historian, Michael Hicks, in his book, Edward V: The Prince in the Tower (2003). My attention to this record was directed by Brad Verity and Matthew Tompkins, whose help is gratefully acknowledged.
The published abstract reads as follows:
"Date: Year 3 of Pontificate"
"William Bille and William Blenkarne have licence to convey their manors or 'dominia' of Hesilden and Morton to Thomas Lumle, knight, 'dominus' of Lumle, for his life, with remainders over, and the manor of 'dominium' of Bewtrove to Thomas Lumle, esquire (son of George Lumle, knight, the son of Thomas Lumle, knight) and Margaret wife of the said Thomas Lumle, esquire, for their lives, with remainder to the right heirs of the said Thomas Lumle, esquire."
The above record is dated the 3rd year of William Dudley, Bishop of Durham. According to Wikipedia, Bishop Dudley was nominated to Durham on 31 July 1476 and was consecrated between 1 September and 12 October 1476. Thus year three of his pontificate would fall in 1478-1479. The record indicates that Thomas Lumley, esquire, and his wife, Margaret, were granted the manor of Beautrove, Durham in the lifetime of his grandfather, Thomas Lumley, Knt., 2nd Lord Lumley. As such, this confirms that he is definitely the Thomas Lumley, esquire, "of Beutroby, Durham," whose inquisition is mentioned earlier in this post."
Link to the post
https://groups.google.com/forum/#!msg/soc.genealogy.medieval/7g__mErVKHs/SjdVE1i8Rm8J
Link to the published abstract
https://archive.org/details/ldpd_11897906_035/page/154
Thomas Lumley and Margaret his wife are also mentioned in the Durham IPM of his grandfather Sir Thomas Lumley, Knt., 2nd Lord Lumley, who died 1 April 1485. An abstract of the IPM was published in the 44th Annual Report of the Deputy Keeper of the Public Records, pp. 451-452
https://archive.org/details/annualreportdep06offigoog/page/n486
If there are no objections, could Bree or another pre-1500 certified person change her name from Elizabeth to Margaret and add the two documents as souces, thanks.