Hogwarts/Ilvermorny Houses

[Takanomiya Hijiri]

To be fair, that's probably the criteria the Sorting Hat actually uses.

Plz.
The sorting hat would never be so arbitrary!

No, it judges people based on the tried and tested method of "where did I put the rest of their family? Just chuck 'em in that house, it'll be fiiiine"...
I'm pretty sure the only character who wasn't put in the same house as their parents was Hermione... and only because her parents didn't actually go to Hogwarts.