Hmm!
Perhaps the town priest asked you to take her to some big orthodox priest at the Vatican-equivalent to make sure that Liz isn't possessed, or in danger of becoming an uncontrolled gateway to Hell or something. Or maybe they just asked you to supervise her...make sure she doesn't fall to the dark side...
Hmm. Doesn't seem like they'd assign you to do something open-ended in duration though. More like, "Escort her to the Bishop's Chancellry in Ulm, where she can be ritually cleansed before the Unholy lays its mark on her," or something...
Then events in the game make that directive obsolete, but we become an adventuring party instead.