Sorry Robin, it almost needs to go into the too hard basket.
There are 6 profiles with the name Paterna, some of them have themselves as their own mother, and two others have different parents, though as far as I can understand, her parents are unknown. She also was one of the wives of Ramiro I, King of the Asturias, but I think may have another husband on WikiTree.
I've followed some of the discussions on the Soc Genealogy Medieval site over the years and I think the problem with many of these early Spanish lines, is that there are very few original sources that still exist from that time period, and because many of the names are the same, it's often difficult to work out how they might interrelate. Because there is so little actual evidence, there are many, often contradictory, theories about how these people all fit together into family groups.
If no one else steps forward, I'll see what I can do, but it's not going to be a quick fix.
