About Elizabeth Chaucer
(book)Mistress of the Monarchy by Alison Weir: (about Elizabeth, daughter of Geoffrey Chaucer and his wife Phillippa de Roet, sister of Katherine de Roet, later wife of Hugh Swynford and subsequently John of Gaunts mistress and later wife.)
Elizabeth Chaucer....was later transferred to Barking (one of the most exclusive abbeys in the land) because her cousin Margaret Swynford (daughter of Katherine and Hugh Swynford) was there. Also two of Katherine's sons by John of Gaunt patronized Barking Abbey in which their half sister Margaret, lived. (this coincides) with the likelihood of Margaret's birth occuring at a time when Katherine was bearing children with Hugh Swynford.