Clarice Foster is a level 17 quest giver located in the Pools of Vision in the tauren city of Thunder Bluff.
She starts the quest 
[15] Until Death Do Us Part.
See List of Thunder Bluff NPCs.
Trivia[]
Clarice Foster is actually a mix of names from the movie Silence of the Lambs where Jodie Foster is playing the part for Clarice Starling who is meeting Hannibal "the Cannibal" Lecter.