i almost wrote "heretic" i mean hereditary family names, noble positions and maybe even visual treats would be the key to a lot of such problems. with every (sentient) being standing somewhere in a tree of where they derived from, one could even manage them getting artifact weapons and armor etc from their parents after their demise FUN.
Time to pour a bit of cold water on this stuff. Pretty much every character in the game is related to pretty much every other character, within a site for certain and even at a civilization level as characters move around. This is a function of the small initial size of the population, the rapid increase in that population and the small amount of time that in most cases passes between Year 0 and the end of world generation, pretty much everybody is royalty basically.
If I was to add drow then whole site would be the holdings of a single holding with everybody other than the slaves which would ideally be numerous would be members of the great house. There would be a special sorcerer caste for males (cannot do wizards yet) and a priestess caste for males, both of them having inherant interactions to ape magical powers. The top positions in the government would be restricted to the priestess caste but would also be hereditery, so the matron mother position will go to one of random priestess daughters she manages to produce (castes are non-hereditery) if not then to a random other priestess in the same site.
Drow society is actually pretty simple, there are only really three groups, the priestesses who are in charge, the slaves who are there to do the menial work (this includes being tortured for amusement
) and then there is everybody else, male sorcerers/wizards are in the everybody else category as far as status is concerned. One issue I can think of is the need to exclude members of the priestess caste from having slave status if her parents are slaves, it does not really make sense to have enslaved priestesses about the place, though one could end up with a drow of slave background becoming a priestess.