2nd wife
(2) Hildegarde de Lorraine, d. Jerusalem, 1 April 1046 [Martyrology of the abbey of Ronceray, quoted from Marchegay, 395, n.3; Halphen (1906), 11; Annales de Saint-Aubin, Halphen (1903), 4 (date only), among other annals].
The cartulary of Ronceray provides the only indication of Hildegarde's origin: "... religiosa atque piisima comitissarum, domna Hildegardis, quam scilicet ut credimus et in rebus manifestum est, omnium conditor Deus a Lothariensium partibus, de regali progenie ortam, in hos occidentales terrarum fines ad restaurationem destitutarum olim ecclesiarum perduxit ..." [Halphen (1906), 11, quoting the cartulary of Ronceray]. One plausible conjecture is that she was somehow related to the counts of Nordgau, a Lotharingian family of royal descent in which the name Hildegarde is known to have occurred [see the short discussion in Settipani (1997), 253-4].
http://sbaldw.home.mindspring.com/hproject/prov/fulk0003.htm