Julio-Claudian marriages

I shall go mad if I keep poring over family trees of Julio-Claudian emperors and intermarried noble families of the time. It's because in some cases I want to make an argument that Tacitus wants us to be aware that, for instance, this historical figure is closely related to another one, even if he doesn't explicitly mention it, because they share traits in common or end up in similar situations.

The problems are, of course, that (a) he, well, doesn't explicitly mention it; (b) as is often the case in aristocratic families of any period, the degrees of intermarriage are mind-boggling and who's related to whom can't be significant all the time; and (c) often details of those family trees are prosopographical fantasies -- logical, well-argued fantasies, but not explicitly attested.

Consider, if you will, various female relatives of the emperor Nero. ( This is fairly long. I expect you'll go mad, too -- but there's a diagram. )