Girl who works the oracle (6)
I believe the answer is:
carole
'girl' is the definition.
'works the oracle' is the wordplay.
'works' is an anagram indicator (work can mean to twist or convulse).
'oracle' anagrammed gives 'CAROLE'.
'who' is the link.
(Other definitions for carole that I've seen before include "<196> - King, US singer" , "girl" , "- Lombard, US actress" .)