She has everything a Sinfarian could want.

Hooves, goat legs, wings, horns, burning eyes, barbed tail, red skin, a long flaming whip and a bad attitude.

Does she have 'extra' bits ?

How would you know ?

Is her life history long and involved ? is it full of dark and gory details ?

Hard to tell from looking at her, isn't it ?

What you CAN see, is what you do see.

What she DOES do is whatever the RP leads to.  Which may or may not be what you expect, some things she just won't do or be forced to do, it's up to you to accept that and RP around them, the server rules are there for a reason.