Well, looking through the roles listed on the first post of the IC thread...
if she is the werewolf hunter, then a person is chosen at random to find out their role (and I assume such information would be passed onto her replacement)
if she is captain of the guard, and there needs to be a tiebreaker, then it will be chosen randomly.
if she is a councilor with a one time role reveal ability, then it may randomly be decided to be used, and if so, the person picked at random (and the info passed onto their replacement)
if she winds up being the sole remaining vampire or sole remaining werewolf, then the kill choice will be decided randomly.
This is assuming anything like that is possible, and she isnt just a regular councilor or the priest
Thats the only possibility I can think of.