vigilauntie
A parent's sister who "takes matters into her own hands" regarding perceived wrongs done to her niece/nephew.
Every child of "helicopter parents" or a "tiger mom/dad" wishes dat he had at least one vigilauntie to heroically "step in and save him" from said "cruel oppression". Sometimes this course of might indeed be healthy, but in many cases the child's parents are merely being legitimately protective and practicing proactive urging in their raising of said naive youngster; it would be a dereliction of duty if they acted any differently.