Vertically - father to son.
Horizontally - siblings.
Where it says Con (which stands for conjoined) it means they are married or a couple (I put a heart to make it easier for those who aren't used to family trees) -
I used a standard family tree design and simplified it.
These really are just a regular/normal/standard family tree. Check out the diagonal rubbish Wikipedia posts instead XDD.
This first family tree is the one Kane describes in Chapter 18 - mind you this is how he knows it and serves as an explanation to the conversation he has with Castalia.
So practically it was my fault when I wrote down the whole speech for Kane I forgot an extra "great", hence the confusion as one of the generation got lost between the lines.
Same happened with the Italian as I should have used bis-bisnonno! In the end I just put "ancestor" in both languages but a family tree should fix all the problems.
SPOILER - The Gem of the Mediterranean Sea:
The second family tree is the new one, right after The Gem of the Mediterranean Sea.
I took the old one and modified it by adding the characters we know in color as we see them in the comic (this should come as a visual aid).
As you may see the only differences are the addition of Pandora next to Old Cosimo and shifting Kane up one generation next to Villy whom he thought to be his father but is, in fact, his half brother :)
Everything else stayed the same.
You actually only need the top 3 rows as those are the characters we met. The other ones are ancestors.
The third Family tree is the Next Generation. In case of extra breakdown I further explain it here