After reading this twitter I think maybe she´s a Cambion ( It seems alu-fiends are not in 5e anymore)
https://twitter.com/Cromwelp/status/1304117852564226051Nimue
@Nimue_RPG
·
Sep 10, 2020
Replying to @Cromwelp
Looks great! That demon (devil?) up there gives me the creeps.
Very Games Michael
@Cromwelp
Cambion friends are best friends
IIRC Raphael is a cambion too. Maybe their plots are related?