Neutral as in not affiliated with either Heaven or Hell.
As for how she would fit in with the plot... Well, she'd be another troublemaker, but one that is intended to have no redeeming qualities.
she goes around and gives some random people some magic trinkets. Thus providing Ian plenty of chances to either fight someone that goes a bit power-hungry when they have a power-granting item, or a chance for Ian to talk a person down before they wind up seriously hurting someone.