"The Reynold de Dunstanville who appears in the Pipe Roll of 1130 for Wiltshire and Surrey seems much more likely to be a member of the family who were successors of the Wiltshire Domesday tenant Humphrey de Insula, than to be the illegitimate son of Henry I who was known by the same name and later became Earl of Cornwall. If this is correct, his sister Gundred was not an illegitimate daughter if Henry I.
The reconstruction of the Dunstanville family in the early 12th century is difficult, but the earliest genealogically firm ground comes with two brothers: Robert de Dunstanville, also known as Robert son of Reynold, and Alan de Dunstanville. Robert first appears as a witness to several charters of the Empress Matilda, in and around 1141, and was dead by 1168; Alan appears at more or less the same time, and was dead by 1156.
Eyton [Antiquities of Shropshire, vol.2, pp.268-283 (1854-60)] gave a reconstruction of the Dunstanville family, in which Reynold, the father of Robert and Alan, was the same man who married Adeliza de Insula, the heir of the Domesday tenant. This Reynold was dead by 1114, and Eyton concluded that the Reynold of 1130 was the king's son. But this scheme involves severe chronological difficulties - it would imply that Robert was active by 1121 (and probably by 1110), whereas the evidence suggests that Robert's nephews could have been born no earlier than about 1150.
It is more natural to assume that the father of Robert and Alan was the same Reynold de Dunstanville who appears in the Pipe Roll of 1130 (and probably the same who appears at the court of the Bishop of Bath in 1121). This is the reconstruction given by Farrer [Honors and Knights' Fees, vol.3, p.37 (1923-5)].
Some confirmation that these siblings belonged to the Dunstanville family, rather than being illegitimate children of the king, comes from the occurrence of the uncommon name Gundred itself. Before 1121, a Reynold de Dunstanville was a benefactor of Lewes Priory, which had been founded by William de Warenne and his wife Gundred [Dugdale, Mon. Angl., vol.5, p.14; Victoria County History, Wiltshire, vol.12, p.185]. Also, a charter for the Abbey of la Sauve Majeure from the late 1090s, the grantor of which K.S.B. Keats-Rohan identifies as Walter de Dunstanville, includes the name Gundred twice, apparently in a list of members of the family [Domesday People I, p.276; Cal. Docs France, vol.1, no 1238]." 1