[NSFW] Can someone explain to me the following piece of information found on the web?

What’s to explain? The Flowers in the Attic series is all about imprisonment of children and rampent incest. They’re also pretty well written.

Check the English definitions of half-uncle, niece, half-brother, and stepmother, and you’ll be able to do as well understanding that as anyone else who hasn’t read those. But it sounds like you might need more detail on what happened in the stories to fully understand who begat whom and how that affects the relationship terms.

Basically, the usual meanings of family relationship terms assume people won’t produce children with close family members, and don’t involve one person producing children with multiple generations in the same family, etc.

Seems to be a theme here. What more needs to be explained?