Girl with capacity to contain anger over mischief (9)
I believe the answer is:
diablerie
'mischief' is the definition.
(thesaurus)
'girl with capacity to contain anger over' is the wordplay.
'girl' becomes 'Di' (short for Diane or Diana).
'with capacity' becomes 'able'.
'to contain' is an insertion indicator.
'anger' becomes 'ire' (ire is intense rage).
'over' says the letters should be written backwards.
'ire' reversed gives 'eri'.
'able' placed around 'eri' is 'ablerie'.
'di'+'ablerie'='DIABLERIE'
(Other definitions for diablerie that I've seen before include "association with Satan" , "dark arts" .)