Perhaps adding Weir's and Cawley's words into the shut-down Overview would be useful.
“Britain’s Royal Families: The Complete Genealogy”, p. 47
1 Euphenia – she was perhaps the child born in late July or early August, 1101, at Winchester, who died young.
MEDLANDS – England, Kings 1066-1837: Chapter 1. Kings of England 1066-1135 (Normandy)
1. [daughter (Winchester Jul/Aug 1101-died young). According to Weir, a legitimate daughter of King Henry's was born in late Jul or early Aug 1101[173]. She names her Euphemia. The primary source which confirms the birth of a child at that time has not yet been identified. It is possible that there is confusion with the birth of the king's daughter Matilda, probably born in the following year. All the contemporary chronicles so far consulted state that the king had only two children by his first marriage. The name Euphemia appears improbable. The earliest reference to this name so far found among noble families in the British Isles is the mother of Robert de Brus Lord of Annandale (who died in 1191), her precise parentage being unknown although she is recorded as neptis of Guillaume "le Gros" Comte d'Aumâle and Lord of Holderness (who died in 1179). The name is not found among the immediate ancestors of the legitimate children of King Henry, and it is unclear why the king would have given a non-family name to his eldest daughter.]
https://fmg.ac/Projects/MedLands/ENGLAND,%20Kings%201066-1603.htm#_...
