The Annalista Saxo names "Bertrada, soror Suanehildis comitisse de castro quod dicitur Lon in Hasbania, cuius filius fuit Arnoldus comes Mogotiensis prefectus" as wife of Graf Dietrich (identified as Dietrich I Graf von Katlenburg).... [No] primary source has been identified which indicates that Bertrada was the daughter of Dirk III Count of Holland. Nevertheless, from a chronological point of view Count Dirk is the most likely father, assuming that Bertrada was a member of this family. "Arnoldus comes Mogotiensis prefectus" in this passage must be identified as Arnaud [I] Comte de Looz, who is recorded as the son of Emmo Comte de Looz. If that is correct, Suanehildis was the wife of Emmo. From a chronological point of view, the suggestion is feasible: the birth of the children of Count Dirk III must be dated to [1010/35], while Comte Emmo´s children were probably born in [1040/60]. The necrology of Liège Saint-Jacques points to this being the correct solution when it records the death 31 Mar of “Spannehildis comitissima de Los” and her donation.
Verdonk indicates that she died in 1100 on a pilgrimage to Rome. The Vita Andreæ, first abbot of Averboden, in the Chronicle written by Nicolas Hogeland Abbot of Middelburg, records that "comitis Arnoldi Lossensis" descended "ex parte matris" from "Cliviæ comitibus", which would be inconsistent with this hypothesis but...Klaversma notes that this source is a 17th century forgery and is therefore unreliable. 1