While Cawley acknowledges that Wegener speculated that the wife of Duke Arnulf was Judith of Friuli, and Cawley even links the two together in his database, he points out that this is unlikely based on the fact that Judith must have been born too early to be the mother of Arnulf's children.
If the families are related (which appears to have been speculated based solely on the basis of the introduction of the names Judith and Eberhard into Arnulf's family), it is just as possible that Judith's daughter (by an unknown husband) was Arnulf's wife.