The whole treating good and evil drow as actual subrwves in the game is silly. It makes no sense in any way. Drow is an elven subrace. They can be good or devil. Culturally speaking, drow tends to be devil because theur cities are dominated by Lloth, but they have always been capable of breaking away. That's where Ellistraee comes in. She willingly stayed with the driw pantheon so be in position to influence drow to turn from.the darkness of Lloth. There are also other non Loth drow dieties and even non driw interloper like Ghaunduar.
Again, treating drow as a separate race and these two as different subraces is dumb.