Naughty niece after honour at last redeemed for good behaviour (9)
I believe the answer is:
obedience
'good behaviour' is the definition.
(being obedient or well-behaved)
'naughty niece after honour at last redeemed' is the wordplay.
'naughty' indicates anagramming the letters.
'after' says to put letters next to each other.
'honour' becomes 'OBE' (Order of the British Empire award).
'at last' indicates one should take the final letters.
The final letter of 'redeemed' is 'd'.
'niece' is an anagram of 'ience'.
'obe'+'d'='obed'
'ience' put after 'obed' is 'OBEDIENCE'.
'for' is the link.
(Other definitions for obedience that I've seen before include "Submission to another's authority" , "Quality desired in dogs and troops" , "Compliance with rules" , "Submissiveness" , "Respect" .)