That woman with nothing, nice at heart and courageous (6)
I believe the answer is:
heroic
'courageous' is the definition.
(thesaurus)
'that woman with nothing nice at heart' is the wordplay.
'that woman' becomes 'her' (I've seen this before).
'with nothing' becomes 'o' (I've seen this in other clues).
'at heart' means to look at the middle letters.
The middle letters of 'nice' are 'ic'.
'her'+'o'+'ic'='HEROIC'
'and' acts as a link.
(Other definitions for heroic that I've seen before include "Extravagant" , "lion-hearted" , "Gallant" , "Fearless, valiant" , "Courageous - daring" .)