A commenter on the most recent part of "An Afternoon Lesson" voiced some confusion over just what that tangled Slytherin-Gryffindor family connection is. I drew up a family tree, which, along with some notes, is beneath the cut. Felt very odd to be working on a tree without any shading for traits for which I must determine the mode of inheritance. (It would be fun to play around with that for the Parseltongue ability.)
And because I neglected to mention an expected update date in my previous journal entry: the next part of "An Afternoon Lesson" will be posted some time Friday night.
I did not map the split within the Slytherin family, caused by Leonius Slytherin's defection to the Council several centuries prior to the events in Nullifier, which led to the formation of the Gryffindor line. For the curious: Leonius took up the surname "Gryffindor" during the war to further separate himself from the rest of his family. And now that the ancient history is out of the way, here is the less ancient history:
The numbered individuals correspond to people who have been explicitly named within Nullifier or any of the related side stories. The order of the children from left to right does not always correspond with their order of birth, except for the bottom two levels of the tree, where it does.
I did not plot out the families of three of the Gryffindor women, for space reasons.
The individuals are:
1. Aulus
2. Warin
3. Alviva (d)
4. Emmeline
5. Geoffrey
6. Tobias
7. Salazar
8. Mathias
9. Marcus (d)
10. Davin
11. Godric
12. Cassandra
As you can see, Warin and Geoffrey are cousins through the Slytherin family. Salazar and Godric, therefore, are direct cousins through their mothers and second cousins via their fathers.
I'm happy to answer any further questions, if anyone has any, or clarify any remaining confusion.