Disturbing rich site maybe provided her with mystery material (8)
I believe the answer is:
christie
'her with mystery material' is the definition.
I can't tell whether this definition defines the answer.
'disturbing rich site maybe' is the wordplay.
'disturbing' is an anagram indicator (I've seen this in other clues).
'maybe' indicates anagramming the letters.
'rich' with letters rearranged gives 'chri'.
'site' with letters rearranged gives 'stie'.
'chri'+'stie'='CHRISTIE'
'provided' is the link.
Can you help me to learn more?
(Other definitions for christie that I've seen before include "family with lots to do?" , "Author of Murder on the Orient Express" , "See 15" , "Agatha ..., mystery story writer" , "Agatha ---, novelist; John ---, murderer" .)