Sistager
It derives from "sister" and "manager". It refers to a sister who servers as a manager to her siblings.
A sistager will tell you exactly what to wear and how to speak.
My sistager answers calls on my behalf.
My sistager answers calls on my behalf.
sistagal
a mildly ghetto term for friend who is a girl, expresses that you consider this person a friend can even be used aggressively in an argument.
“Calm down sistagal, it’s not a big deal”